When giving a model of how believers are to pray, Jesus begins with the words "Our Father":
Matthew 6:9
9 After this manner therefore pray ye: Our Father which art in heaven, Hallowed be thy name.
This is repeated in Luke 11:2. The fact that believers are children of God is a major theme in the New Testament (Matthew 7:11, John 1:12, Galatians 3:26, 4:4-6: 1 John 5:1, etc.), as is the fact that Jesus is the Son of God (John 3:16, Matthew 8:29, Mark 1:1, Luke 1:35, etc.).
In contrast, Muhammad entirely rejected the concept of God being a father to anyone:
Surah 37:151-52
151 Indeed, it is one of their ˹outrageous˺ fabrications to say,
152 "Allah has children." They are simply liars.
Surah 5:18
18 The Jews and the Christians each say, "We are the children of Allah and His most beloved!" Say, ˹O Prophet,˺ "Why then does He punish you for your sins? No! You are only humans like others of His Own making. He forgives whoever He wills and punishes whoever He wills. To Allah ˹alone˺ belongs the kingdom of the heavens and the earth and everything in between. And to Him is the final return."
This teaching is reiterated in Surah 2:116, 17:111, 19:35, 19:88-92, 21:26, 23:91, 39:4, 43:81, and 72:3.
Jesus, just as the Old Testament prophets (Genesis 6:1-4, Exodus 4:22, Deuteronomy 14:1, 32:5-6: 2 Samuel 7:14, Job 1:6, 2:1, 38:7, Psalm 2:7, 2:12, 73:15, 89:26, Isaiah 43:6, 63:16, 64:8, Jeremiah 3:19-20, Hosea 1:10, Malachi 2:10), taught a God that was a Father, with human beings as His children. He did so dozens of times, and taught us to open our prayers with that fact. Muhammad decried the entire concept of God as father.
In the Bible, Jesus teaches very clearly that if someone marries a person who is divorced for any other reason than fornication, they have committed adultery:
Matthew 5:31-32
31 It hath been said, Whosoever shall put away his wife, let him give her a writing of divorcement:
32 But I say unto you, That whosoever shall put away his wife, saving for the cause of fornication, causeth her to commit adultery: and whosoever shall marry her that is divorced committeth adultery.
This is reiterated in Matthew 19:3-9, Mark 10:2-12, and Luke 16:18.
In contrast, Muhammad not only taught that marrying a divorced person was permissible (Surah 2:230), he also personally married a divorced woman, whom his own stepson Zaid had divorced because of Muhammad, as covered in this article:
Surah 33:37
37 And ˹remember, O Prophet,˺ when you said to the one for whom Allah has done a favour and you ˹too˺ have done a favour, "Keep your wife and fear Allah," while concealing within yourself what Allah was going to reveal. And ˹so˺ you were considering the people, whereas Allah was more worthy of your consideration. So when Zaid totally lost interest in ˹keeping˺ his wife, We gave her to you in marriage, so that there would be no blame on the believers for marrying the ex-wives of their adopted sons after their divorce. And Allah's command is totally binding.
Moreover, in a bizarre verse, which actually contains the words of Umar (Sahih al-Bukhari 402), Muhammad threatens his wives with divorce, and then intimates that he might remarry women who have been divorced:
Surah 66:5
5 Perhaps, if he were to divorce you ˹all˺, his Lord would replace you with better wives who are submissive ˹to Allah˺, faithful ˹to Him˺, devout, repentant, dedicated to worship and fasting - previously married or virgins.
Whereas Jesus taught that remarriage after divorce is strictly forbidden, Muhammad taught the opposite, and additionally broke Jesus's commandment personally when he married Zaynab.
Jesus taught that in Heaven, there will be no marriage:
Mark 12:23-25
23 In the resurrection therefore, when they shall rise, whose wife shall she be of them? for the seven had her to wife.
24 And Jesus answering said unto them, Do ye not therefore err, because ye know not the scriptures, neither the power of God?
25 For when they shall rise from the dead, they neither marry, nor are given in marriage; but are as the angels which are in heaven.
This is found in the parallel accounts in Matthew 22:30, and Luke 20:35.
In contrast, Muhammad taught that believers will be married to women in Heaven, and have intercourse with them for all eternity:
Surah 2:25
25 Give good news ˹O Prophet˺ to those who believe and do good that they will have Gardens under which rivers flow. Whenever provided with fruit, they will say, "This is what we were given before," for they will be served fruit that looks similar ˹but tastes different˺. They will have pure spouses, and they will be there forever.
This is reiterated in Surah 3:15, 4:57, 36:55-56, 37:48-49, 38:52, 43:70-71, 44:54, 52:20, 55:56, 55:70-74, 56:22-23, 56:35-37, and 78:33. These wives are also mentioned in Sahih al-Bukhari 2796, 3254, 3327, 4879-80, Sahih Muslim 2834a, 2834c, 2834e, Sunan Ibn Majah 4333, and Jami at-Tirmidhi 1663, 2522, 2536, 2735.
Muhammad's entire concept of Heaven is completely different from the one in Christianity, and even Judaism. The Bible describes the eternal state as dwelling with God in a totally remade earth (Isaiah 65:17-25: 1 Corinthians 15:20-28, Revelation 21:1-4), not Muhammad's heaven of intercourse, which is apparently inside of a 60 mile-wide pearl (Sahih al-Bukhari 3243, 4879-80, Sahih Muslim 2838a-c, Jami at-Tirmidhi 2528). In creating a heavenly paradise of his own desire, he again contradicted what Jesus Christ taught.
In the Sermon on the Mount, Jesus forbade vain, repetitious prayer:
Matthew 6:7-8
7 But when ye pray, use not vain repetitions, as the heathen do: for they think that they shall be heard for their much speaking.
8 Be not ye therefore like unto them: for your Father knoweth what things ye have need of, before ye ask him.
However, Muhammad taught his followers to do what is the definition of a vain repetition:
Sahih Muslim 597a
Abu Huraira reported Allah's Messenger (ﷺ) as saying:
If anyone extols Allah after every prayer thirty-three times, and praises Allah thirty-three times, and declares His Greatness thirty-three times, ninety-nine times in all, and says to complete a hundred:" There is no god but Allah, having no partner with Him, to Him belongs sovereignty and to Him is praise due, and He is Potent over everything," his sins will be forgiven even If these are as abundant as the foam of the sea.
This is also narrated in Sahih al-Bukhari 843, 3705, 5361-62, 6318, and Sahih Muslim 595a, 596a, 597b, 2727a, 2728a-b.
In some of these narrations, Muhammad recommended that one do this before bed, but in others, as highlighted above, he recommended it after every prayer. That would amount to 500 repetitions per day.
Elsewhere, Muhammad taught the chanting of a yet another phrase 100 times per day:
Sahih al-Bukhari 6405
Narrated Abu Huraira:
Allah's Messenger (ﷺ) said, "Whoever says, 'Subhan Allah wa bihamdihi,' one hundred times a day, will be forgiven all his sins even if they were as much as the foam of the sea.
This is also narrated in Sahih Muslim 2691, and Jami at-Tirmidhi 3468.
Of course, everyone who performs vain repetitions, when called out for doing so, will firmly deny that whatever they are doing is not vain repitition. This is immaterial. If chanting 3 prayers 33 times each, potentially multiple times per day, is not vain repitition, and if chanting a single phrase 100 times per day is not vain repitition, then nothing is. God does not hear a person because they say the same thing over and over again. That is what Jesus Christ taught, and Muhammad contradicted.
Returning again to the Sermon on the Mount, notice Jesus Christ's teaching on the topics of prayer, giving, and fasting:
Matthew 6:1-8, 16-18
1 Take heed that ye do not your alms before men, to be seen of them: otherwise ye have no reward of your Father which is in heaven.
2 Therefore when thou doest thine alms, do not sound a trumpet before thee, as the hypocrites do in the synagogues and in the streets, that they may have glory of men. Verily I say unto you, They have their reward.
3 But when thou doest alms, let not thy left hand know what thy right hand doeth:
4 That thine alms may be in secret: and thy Father which seeth in secret himself shall reward thee openly.
5 And when thou prayest, thou shalt not be as the hypocrites are: for they love to pray standing in the synagogues and in the corners of the streets, that they may be seen of men. Verily I say unto you, They have their reward.
6 But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father which is in secret; and thy Father which seeth in secret shall reward thee openly.
7 But when ye pray, use not vain repetitions, as the heathen do: for they think that they shall be heard for their much speaking.
8 Be not ye therefore like unto them: for your Father knoweth what things ye have need of, before ye ask him.
16 Moreover when ye fast, be not, as the hypocrites, of a sad countenance: for they disfigure their faces, that they may appear unto men to fast. Verily I say unto you, They have their reward.
17 But thou, when thou fastest, anoint thine head, and wash thy face;
18 That thou appear not unto men to fast, but unto thy Father which is in secret: and thy Father, which seeth in secret, shall reward thee openly.
The constant thread running through these teachings is that one should perform certain good deeds privately.
In contrast, one can look at the practices of Muslims, as taught to them by Muhammad:
Muhammad's religion teaches the exact type of outward, hypocritical, vain religiosity that Jesus Christ rebuked. Also, because none of these things are ever required of believers by God in the New Testament, Muhammad squarely falls under the condemnation of the following:
Mark 7:6-7
6 He answered and said unto them, Well hath Esaias prophesied of you hypocrites, as it is written, This people honoureth me with their lips, but their heart is far from me.
7 Howbeit in vain do they worship me, teaching for doctrines the commandments of men.
Jesus Christ, throughout His ministry, frequently prophesied of His own death and resurrection (Matthew 12:40, 16:21, 17:11-12, 17:22-23, 20:17-19, 20:22-23, 20:28, 21:33-46, 26:1-2, Mark 8:31, 9:12, 9:31, 10:32-34, 10:38-39, 10:45, 12:1-12, Luke 9:22, 17:24-25, 18:31-33, 20:9-19, John 2:19-22, 3:14-16, 10:15-18, 12:32-33).
For example:
Matthew 17:22-23
22 And while they abode in Galilee, Jesus said unto them, The Son of man shall be betrayed into the hands of men:
23 And they shall kill him, and the third day he shall be raised again. And they were exceeding sorry.
On the contrary, Muhammad seemingly denied that Jesus died on the cross, and certainly denied that He died as a substitutionary atonement for mankind, as Jesus taught (Matthew 20:28, 26:27-28, Mark 10:45):
Surah 4:157-58
157 And for boasting, “We killed the Messiah, Jesus, son of Mary, the messenger of Allah.” But they neither killed nor crucified him - it was only made to appear so. Even those who argue for this ˹crucifixion˺ are in doubt. They have no knowledge whatsoever - only making assumptions. They certainly did not kill him.
158 Rather, Allah raised him up to Himself. And Allah is Almighty, All-Wise.
Therefore, Muhammad denied one of the culminating events of Jesus Christ's entire ministry, which was prophesied by both Jesus Himself and the Old Testament prophets, as covered at length in this article.
In the Quran, Muhammad repudiated the Christian claims that only believers in Christ will be saved:
Surah 2:111
111 The Jews and Christians each claim that none will enter Paradise except those of their own faith. These are their desires. Reply, ˹O Prophet,˺ "Show ˹me˺ your proof if what you say is true."
In response to the above challenge to "Show me your proof if what you say is true" - allegedly given by the same God who wrote the Gospel (Surah 5:46-47, 5:66, 5:68, 5:110, etc.), the following explicit proof can be offered:
John 3:36
36 He that believeth on the Son hath everlasting life: and he that believeth not the Son shall not see life; but the wrath of God abideth on him.
Other exclusivist statements in Scripture include John 3:18, 8:24, 14:6, Mark 16:16, Acts 4:12 and 1 John 5:12.
As can be clearly seen, Muhammad directly castigates Jesus Christ, in this Quran verse. Jesus said He was the only way, and Muhammad, in so many words, calls Him a liar.
Then, in the Hadith, Muhammad usurps the role of sole mediator (1 Timothy 2:5) from Jesus, and assigns it to himself (Sahih al-Bukhari 4476, 4712, 6565, 7410, 7440, 7510, and Sahih Muslim 193a-e, 194a), even though he himself was a sinner (Surah 40:55, 47:19, 48:1-2, Sahih al-Bukhari 6307).
Muhammad taught that when one is attacked, they are to respond in kind:
Surah 2:194
194 The sacred month for the sacred month; and sacrilege calls for retaliation. Whoever commits aggression against you, retaliate against him in the same measure as he has committed against you. And be conscious of God, and know that God is with the righteous.
Notice what Muhammad did not say. He did not say "defend yourself". He said "retaliate against him in the same measure as he has committed against you". That is taking vengeance. The option to retaliate in-kind is also given in Surah 16:126.
In contrast, Jesus Christ taught not to take vengeance for ourselves when others wrong us:
Matthew 5:38-45
38 Ye have heard that it hath been said, An eye for an eye, and a tooth for a tooth:
39 But I say unto you, That ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also.
40 And if any man will sue thee at the law, and take away thy coat, let him have thy cloak also.
41 And whosoever shall compel thee to go a mile, go with him twain.
42 Give to him that asketh thee, and from him that would borrow of thee turn not thou away.
43 Ye have heard that it hath been said, Thou shalt love thy neighbour, and hate thine enemy.
44 But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you;
45 That ye may be the children of your Father which is in heaven: for he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust.
Also see Luke 6:27-36, and Romans 12:19. The contrast between the above, and the teaching of Muhammad, is striking. The beauty, mercy, and holiness of the teachings of Christ is obvious, and superior to that of Muhammad's.
After He rose from the dead, Jesus commanded His followers to teach all nations, and baptize them in the name of the Father, and the Son, and the Holy Spirit:
Matthew 28:19-20
19 Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:
20 Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen.
Likewise, at the Last Supper, Jesus instructed his followers to observe the practice of breaking bread and drinking wine together, as He was doing, in memory of Him (1 Corinthians 11:23-26):
Luke 22:19-20
19 And he took bread, and gave thanks, and brake it, and gave unto them, saying, This is my body which is given for you: this do in remembrance of me.
20 Likewise also the cup after supper, saying, This cup is the new testament in my blood, which is shed for you.
Yet, in spite of the above commandments, Muhammad did not baptize people in the name of the Father, the Son, and the Holy Spirit, nor did he keep the ordinance of the Lord's Supper in memory of Jesus's death and resurrection.
This shows that Muhammad was not following Jesus. He did not obey what Jesus Christ commanded, nor did he ever explain why he did not baptize, or keep the Lord's Supper. He instead, characteristically, appeared totally ignorant of both ordinances.
Jesus taught many things about Himself that Muhammad completely rejected, including:
The Bible - which is the only record that anyone has for the life of Jesus - teaches an entirely different Jesus to the one Muhammad invented. According to the testimony that Jesus Christ gave about Himself, He is far more than a mere prophet; He is God's anointed Messiah. And, He is certainly not secondary to the sinner (Surah 40:55, 47:19, 48:1-2, Sahih al-Bukhari 6307) Muhammad.
Islam affirms a "Jesus" that has never existed anywhere, and completely contradicts the only Jesus that history or Christians have ever known. But, any religion can affirm that "Jesus", because it is a fictional character invented in order to suit the needs of the one trying to hijack Jesus for their own purposes.