Mark 13:8-20
8 For nation shall rise against nation, and kingdom against kingdom: and there shall be earthquakes in divers places, and there shall be famines and troubles: these are the beginnings of sorrows.
9 But take heed to yourselves: for they shall deliver you up to councils; and in the synagogues ye shall be beaten: and ye shall be brought before rulers and kings for my sake, for a testimony against them.
10 And the gospel must first be published among all nations.
11 But when they shall lead you, and deliver you up, take no thought beforehand what ye shall speak, neither do ye premeditate: but whatsoever shall be given you in that hour, that speak ye: for it is not ye that speak, but the Holy Ghost.
12 Now the brother shall betray the brother to death, and the father the son; and children shall rise up against their parents, and shall cause them to be put to death.
13 And ye shall be hated of all men for my name's sake: but he that shall endure unto the end, the same shall be saved.
14 But when ye shall see the abomination of desolation, spoken of by Daniel the prophet, standing where it ought not, (let him that readeth understand,) then let them that be in Judaea flee to the mountains:
15 And let him that is on the housetop not go down into the house, neither enter therein, to take any thing out of his house:
16 And let him that is in the field not turn back again for to take up his garment.
17 But woe to them that are with child, and to them that give suck in those days!
18 And pray ye that your flight be not in the winter.
19 For in those days shall be affliction, such as was not from the beginning of the creation which God created unto this time, neither shall be.
20 And except that the Lord had shortened those days, no flesh should be saved: but for the elect's sake, whom he hath chosen, he hath shortened the days.
The Grace New Testament Commentary - Mark 13:12-13
13:12-13 Disciples will be opposed by family as "brother will betray brother to death," and a father will betray "his child" to death. "Children will rise up against parents and cause them to be put to death." Believers can also expect to "be hated by all (i.e., by the world) for My name's sake" (i.e., because of Christ). In this setting it is easy to see how "the love of many disciples will grow cold" (cf. Matt 24:12).
Christ's statement, "But he who endures to the end shall be saved," is often interpreted to mean that one's salvation (i.e., justification) is contingent on perseverance in good works. But keeping this phrase within the context of the discourse yields a different interpretation.
The phrase the end (to telos) does not refer to the end of one's life, but the end of the Tribulation period. The other usage of to telos in this discourse is in Mark 13:7, "but the end is not yet." It refers to the end of the events in the Tribulation leading up to Christ's Second Coming. Theologically the word saved (sozō) has a wide variety of meanings depending on its context. The other usage of saved in this discourse is in v 20 where the word clearly refers to physical preservation from the Tribulation judgments (cf. v 20 discussion). In this sense even some unbelievers will be saved in that they will physically survive the Tribulation.
Verse 13 is not referring to eternal life, which is a present possession of the believer (Eph 2:8-9; Acts 16:31). Here, the verb saved is in the future tense and is conditioned on enduring to the end. Again this discourse concerns the vigilance of disciples who are apt to become "cold" because of deception, economic and political hardships, and persecution by family and the world. Mark 13:13 is a statement that Tribulation believers who endure faithfully will physically survive to the end of the Tribulation so they may enter Christ's kingdom without death. Of course, some faithful believers will be killed during the Tribulation (e.g. Mark 13:12; Rev 6:9-11), but most believers who die will be those unfaithful ones who are swept up in God's judgment upon the sins of this world. Such believers will go to heaven, but will not be saved from death during the Tribulation.
Charles Bing - Grace, Salvation, and Discipleship - He Who Endures to the End, Matthew 24:13 (cf. Matthew 10:22; Mark 13:13; Luke 21:19)
(Salvation) Interpretation: Only someone who continues in good works and faith to the end of his life will receive salvation or prove he was saved.
(Discipleship) Interpretation: Only those of Israel in the Tribulation who are able to endure persecution until the time of Christ's return will be delivered from the hostile nations.
This saying in Matthew and Mark is used by some to teach that professing Christians must persevere in faith and good works in order to prove their salvation is genuine, which is a (Salvation) interpretation.
While those who say professing Christians must persevere in order to prove that they are genuinely saved, they would not admit that perseverance is a work that earns salvation. Of course, this is flawed reasoning, because if perseverance is necessary to prove salvation, then perseverance is necessary for salvation. This is in addition to one's initial faith in Jesus Christ as Savior. Salvation would be by faith plus one's performance, which contradicts the free nature of God's grace. Some might try to avoid this charge by modifying their view to say that true saving faith is a faith that performs, but this does not avoid the error of making works necessary for salvation.
The (Salvation) interpretation understands "the end" to mean the end of one's physical life. But this ignores the unique order and events of the end times about which Jesus is speaking. The context indicates what "the end" refers to. It is clear that Matthew (and Mark) is speaking about conditions in the time of Israel's great Tribulation (which also seems to be the context of a similar saying in Matt. 10:22). In answering the disciples' question about His return (Matt. 24:3), Jesus answers the last question about the end of the age first. When Jesus refers to "the end" in verses 6, 13, and 14, it has the same meaning - the end of the age which concludes with the Tribulation period. In that time of great sorrow, the Jews will be hated and killed by all the nations (Matt. 24:9), betrayed by their own countrymen (Matt. 24:10), deceived by false prophets (Matt. 24:11), and experience lawlessness and lack of natural affection (Matt. 24:12). After verse 13, Jesus' prophecy reveals the details that actually describe His coming (Matt. 24:14-51). Though many of Israel will be killed, those who endure these perils to the end of the Tribulation (not to the end of their physical lives, which is the (Salvation) interpretation) will be delivered ("saved") from their enemies, the nations who hate them. This "last minute rescue" of Israel by Jesus Christ is a clear biblical prophecy (Zech. 12:2-9; Rom. 11:26). This is an example of the word saved referring to deliverance from a danger, not deliverance from hell. Indeed, hell is not mentioned in the passage. This is obviously (Discipleship) because enduring to the end does not relate to eternal salvation but temporal deliverance of God's people. In verse 22, Jesus says, "And unless those days were shortened, no flesh would be saved..." It appears that "no flesh" includes Gentiles among those delivered. The parable of the sheep and goats in Matthew 25:31-46 shows that Gentiles ("nations") will be present at the end of the Tribulation.
Israel's story is a story of God's grace. They were chosen by Him to be a special people. In spite of constant sin, God preserved them throughout their history. He will preserve them in the future as well, not because they deserve it, but because He is faithful to His promise to do so. We who are saved by God's grace are kept saved by grace, and will be glorified ultimately and finally by His grace, not because we deserve it, but because that is God's promise to all who believe (John 3:16; 5:24; Rom. 8:28).