This is part of Christ's great sermon on prophecy, better known as the Olivet Discourse. Our Lord is speaking about the Great Tribulation and the intense suffering that the Jews will have to experience at that time. He says, "For then shall be great tribulation. . . and except those days should be shortened, there should no flesh be saved: but for the elect's sake those days shall be shortened" (Matt. 24:21-22).
Mat 24:13 But he that shall endure unto the end,the same shall be saved.

It is plain to see that the end to which Christ referred is the end of the Tribulation Period, not the end of a person's life. This verse simply means that those who endure to the end of the Great Tribulation will be saved from the intense suffering that the Jews will have to experience at that time.We must remember that "the end" in this passage is not the end of the world, but rather the end of the age, the end of the Temple, the sacrificial system, the covenant nation of Israel, and the last remnants of the pre-Christian era.
STANDS FIRM = The context indicates this "standing firm" is keeping the faith (Matthew 24:10) even in the face of great persecution (Matthew 24:9), betrayal (Matthew 24:10); deception (Matthew 24:11); and great wickedness (Matthew 24:12).

TO THE END = In context, the "end" specifically refers to the end of the temple buildings in Jerusalem.

WILL BE SAVED = The Greek "sozo" (Strongs #G4982) means "to save, deliver, make whole, preserve from danger, loss, and/or destruction." This word is used in the New Testament some 54 times. Fourteen instances concern being delivered from disease or demon possession. Twenty instances regard deliverance from peril or instant death. Another twenty occurrences apply to spiritual salvation.

Being "saved" here refers to being saved physically from the destruction of 70 A.D. Historians record that Christians took heed to Jesus' words and escapes from Jerusalem when Titus briefly withdrew his forces before the final onslaught. Not one Christian died in the conflagration.

In this passage, Christ is not talking about salvation of the soul but salvation of the body.