There are three parables given in Matthew chapters 24-25, two of which are also in Luke's Gospel, all having to do with a command to be watchful of the Lord's return.
They are:
These parables are almost unanimously interpreted to be teaching some form of works Salvation, either explicitly, or implicitly, and they are also used to teach that an unfaithful believer can lose their Salvation. Therefore, it's vital for every believer to have a proper understanding of what's being taught here.
First, there is a parable of a lord and his servants, who have been delegated responsibility when he is away:
Matthew 24:42-51
42 Watch therefore: for ye know not what hour your Lord doth come.
43 But know this, that if the goodman of the house had known in what watch the thief would come, he would have watched, and would not have suffered his house to be broken up.
44 Therefore be ye also ready: for in such an hour as ye think not the Son of man cometh.
45 Who then is a faithful and wise servant, whom his lord hath made ruler over his household, to give them meat in due season?
46 Blessed is that servant, whom his lord when he cometh shall find so doing.
47 Verily I say unto you, That he shall make him ruler over all his goods.
48 But and if that evil servant shall say in his heart, My lord delayeth his coming;
49 And shall begin to smite his fellowservants, and to eat and drink with the drunken;
50 The lord of that servant shall come in a day when he looketh not for him, and in an hour that he is not aware of,
51 And shall cut him asunder, and appoint him his portion with the hypocrites: there shall be weeping and gnashing of teeth.
Luke 12:35-48
35 Let your loins be girded about, and your lights burning;
36 And ye yourselves like unto men that wait for their lord, when he will return from the wedding; that when he cometh and knocketh, they may open unto him immediately.
37 Blessed are those servants, whom the lord when he cometh shall find watching: verily I say unto you, that he shall gird himself, and make them to sit down to meat, and will come forth and serve them.
38 And if he shall come in the second watch, or come in the third watch, and find them so, blessed are those servants.
39 And this know, that if the goodman of the house had known what hour the thief would come, he would have watched, and not have suffered his house to be broken through.
40 Be ye therefore ready also: for the Son of man cometh at an hour when ye think not.
41 Then Peter said unto him, Lord, speakest thou this parable unto us, or even to all?
42 And the Lord said, Who then is that faithful and wise steward, whom his lord shall make ruler over his household, to give them their portion of meat in due season?
43 Blessed is that servant, whom his lord when he cometh shall find so doing.
44 Of a truth I say unto you, that he will make him ruler over all that he hath.
45 But and if that servant say in his heart, My lord delayeth his coming; and shall begin to beat the menservants and maidens, and to eat and drink, and to be drunken;
46 The lord of that servant will come in a day when he looketh not for him, and at an hour when he is not aware, and will cut him in sunder, and will appoint him his portion with the unbelievers.
47 And that servant, which knew his lord's will, and prepared not himself, neither did according to his will, shall be beaten with many stripes.
48 But he that knew not, and did commit things worthy of stripes, shall be beaten with few stripes. For unto whomsoever much is given, of him shall be much required: and to whom men have committed much, of him they will ask the more.
In the Luke passage, the Lord begins by likening himself to a lord returning from a wedding, who expects his servants to answer the door immediately when he knocks (Luke 12:35-38). Then, in both passages, the Lord compares himself to a thief in the night, who servants of a household are to watch for (Matthew 24:42-44, Luke 12:39-40). Finally, the Lord likens himself to a lord who delegated responsibility to a servant when he goes on a journey, and discusses the two possible outcomes for that servant (Matthew 24:45-51, Luke 12:41-48).
It is the third section that mentions drastic consequences for the wicked servant - he will be "cut asunder" (in pieces) (Matthew 24:51, Luke 12:46), "beaten with few/many stripes" (Luke 12:47-48), and appointed "his portion with the hypocrites/unbelievers" (Matthew 24:51, Luke 12:46).
For those who teach that believers can lose their Salvation, the wicked servant is seen as a misbehaving believer. The punishments are seen as describing Hell.
However, this servant is not a believer - they are only a "servant" in the sense that they are a professing Christian. They are appointed their portion with the "unbelievers" (Luke 12:46), because that's what they are.
This is just as in other parables, where a lord allowed tares to be in his field among the wheat (Matthew 13:24-42, covered in detail here), even though the tares are "children of the wicked one" (Matthew 13:38), or how the "husbandmen" lent out a vineyard by a lord represent Christ-rejecting Jews (Matthew 21:33-46, Mark 12:1-12, Luke 20:9-19).
The behavior of the wicked servant - drunkenness and beating other servants (Matthew 24:49, Luke 12:45) - can be done by a believer, but characterizes unbelievers. For instance, the largest branch of apostate Christianity, Roman Catholicism and its children, has been characterized as practically the only organized religion on the planet that doesn't oppose the use of alcohol, and also has besieged, tortured, and killed other Christian groups on a constant basis, for many hundreds of years.
Therefore, this parable speaks to the fact that the Lord has expectations for every single person who claims the name of Christ, even though a vast, vast majority of them simply don't care at all about anything He taught, and will be rendered a corresponding punishment when He returns.
Immediately after the above parable, the Lord gives the parable of the ten virgins, who are waiting for a groom to arrive at a wedding:
Matthew 25:1-13
1 Then shall the kingdom of heaven be likened unto ten virgins, which took their lamps, and went forth to meet the bridegroom.
2 And five of them were wise, and five were foolish.
3 They that were foolish took their lamps, and took no oil with them:
4 But the wise took oil in their vessels with their lamps.
5 While the bridegroom tarried, they all slumbered and slept.
6 And at midnight there was a cry made, Behold, the bridegroom cometh; go ye out to meet him.
7 Then all those virgins arose, and trimmed their lamps.
8 And the foolish said unto the wise, Give us of your oil; for our lamps are gone out.
9 But the wise answered, saying, Not so; lest there be not enough for us and you: but go ye rather to them that sell, and buy for yourselves.
10 And while they went to buy, the bridegroom came; and they that were ready went in with him to the marriage: and the door was shut.
11 Afterward came also the other virgins, saying, Lord, Lord, open to us.
12 But he answered and said, Verily I say unto you, I know you not.
13 Watch therefore, for ye know neither the day nor the hour wherein the Son of man cometh.
The virgins who didn't have oil in their lamps are rejected by the groom.
Notice how closely Matthew 25:11-12 parallels Matthew 7:21-23, which as discussed in this article, has unbelievers, who nevertheless called Jesus "Lord", rejected by Christ on the day of judgment.
Similarly, the virgins without oil, who wanted to be let in by the groom, represent professing Christians who are unbelievers. Their going out to "buy" the oil (Matthew 25:10) most likely represents works Salvation. Consequently, the Lord doesn't know them.
Finally, the Lord gives the parable of the talents:
Matthew 25:14-30
14 For the kingdom of heaven is as a man travelling into a far country, who called his own servants, and delivered unto them his goods.
15 And unto one he gave five talents, to another two, and to another one; to every man according to his several ability; and straightway took his journey.
16 Then he that had received the five talents went and traded with the same, and made them other five talents.
17 And likewise he that had received two, he also gained other two.
18 But he that had received one went and digged in the earth, and hid his lord's money.
19 After a long time the lord of those servants cometh, and reckoneth with them.
20 And so he that had received five talents came and brought other five talents, saying, Lord, thou deliveredst unto me five talents: behold, I have gained beside them five talents more.
21 His lord said unto him, Well done, thou good and faithful servant: thou hast been faithful over a few things, I will make thee ruler over many things: enter thou into the joy of thy lord.
22 He also that had received two talents came and said, Lord, thou deliveredst unto me two talents: behold, I have gained two other talents beside them.
23 His lord said unto him, Well done, good and faithful servant; thou hast been faithful over a few things, I will make thee ruler over many things: enter thou into the joy of thy lord.
24 Then he which had received the one talent came and said, Lord, I knew thee that thou art an hard man, reaping where thou hast not sown, and gathering where thou hast not strawed:
25 And I was afraid, and went and hid thy talent in the earth: lo, there thou hast that is thine.
26 His lord answered and said unto him, Thou wicked and slothful servant, thou knewest that I reap where I sowed not, and gather where I have not strawed:
27 Thou oughtest therefore to have put my money to the exchangers, and then at my coming I should have received mine own with usury.
28 Take therefore the talent from him, and give it unto him which hath ten talents.
29 For unto every one that hath shall be given, and he shall have abundance: but from him that hath not shall be taken away even that which he hath.
30 And cast ye the unprofitable servant into outer darkness: there shall be weeping and gnashing of teeth.
Here, a servant who did nothing with the money that his master gave him is rejected by the master when he returns.
Once again, this waste of potential is something that any believer can do, but the "unprofitable servant" in this parable represents an unbeliever, who has only been delegated a "talent" by the Lord in the sense that every single person on earth has potential to get saved, and live for the Lord thereafter. Those that don't do the bare minimum - putting their faith in Christ - are rejected, in the same way that a servant too lazy to even deliver some money to a bank to earn interest would be rejected by his master.
This parable, like the parable of the servant, also teaches that the Lord will reward faithful servants, even though in the strictest sense, the Lord teaches that even the best Christian is an "unprofitable servant":
Luke 17:10
10 So likewise ye, when ye shall have done all those things which are commanded you, say, We are unprofitable servants: we have done that which was our duty to do.
Since us fulfilling our duty to God (works) still reckons us as unprofitable servants in the strictest sense, it indicates further that the "unprofitable servant" in the parable here represents an unbeliever who is rejected entirely by the Lord, rather than some believer who doesn't do Christ's will to some unspecified degree.
A nearly identical parable is given in Luke 19:11-27, and the same principles apply to it, so it doesn't warrant a complete reprint here. The only real difference is that there are ten servants in that parable instead of the three here.
In closing, it should also be stated that some in the Free Grace camp see the punishments above as missing out on some exalted aspect of the Millennial Kingdom, or even all of the Millennial reign of Christ. Such see the mention of the servant receiving "his portion with the unbelievers" (Luke 12:46) as receiving his portion with the "unfaithful", which is how that is literally translated, and even often rendered, reading that way in dozens of translations.
I think that that is, at the very least, a Biblically defensible position. These are parables. The actual events that they represent may be wildly different than the events taking place in the stories. It may very well be that a servant being "cut asunder", and being "beaten with many stripes" by his master pictures what will turn out to be a rebuke, or chastening, from the Lord, or loss of eternal rewards. It may turn out that bridesmaids knocking at a groom's door without being let in, and a servant being "sent to outer darkness" by his master, represent exclusion of some exalted benefit in Christ's Kingdom. Never forget that we are reading stories meant to give us some impression. All of these succeed in demonstrating how seriously the Lord wants us to be on alert for His coming.
Either way, parables are good supplements to our theology, not the foundation. Our foundation is only built on clear, unambiguous statements. The reason being, parables are easily twisted, as they have a myriad of possible interpretations. To this end, the Lord purposefully gave parables to confound those with proud and wicked hearts who wanted to twist His words, so that "seeing they might not see, and hearing they might not understand" (Luke 8:10, also Matthew 13:13-15, Mark 4:11-12).
As of right now, though, I favor the view that the "evil/unprofitable servant", and "foolish virgins" represent evil, apathetic, and apostate Christianity, and serve primarily as a warning to anyone that would read them in the coming 2,000 years to diligently seek the truth regarding Christ and His coming, as well as reminders to believers as to how important it is to stay watchful, sober, and alert while waiting for Christ to return.
In summary, none of these passages teach that without some unspecified level of obedience, a believer will go to Hell. Any person who has ever put their faith in Jesus Christ "has Everlasting Life, and shall not come into condemnation; but is passed from death unto life" (John 5:24), as is discussed in many other articles on this site.