Matt 24:13 in the KJV reads:
But he that shall endure unto the end, the same shall be saved.
The Greek reads:
ὁ δὲ ὑπομείνας εἰς τέλος οὗτος σωθήσεται
The Greek literally reads, "But the one who endured to the end, this one will be saved." Such emphasises that the focus is on the individual who must persevere. Further, the Greek uses the aorist of the substantivized participle (ὑπομείνας) which refers to a completed act of endurance that can provide salvation. Such flies in the face of those who claim that such admonitions are merely descriptive instead of being prescriptive.
Elsewhere, in Rom 8:12-13, we read:
Therefore, brethren, we are debtors, not to the flesh, to live after the flesh. For if ye live after the flesh, ye shall die: but if ye through the Spirit do mortify the deeds of the body, ye shall live.
Some may object to this being used against eternal security as, in their view, Paul was speaking of physical death, as noted in the death of disobedient Christians at Corinth who partook of the Eucharist unworthily (1 Cor 11:30). Notwithstanding, Paul's general usage of "death" includes both physical and spiritual aspects, and often these two are interchangeable (e.g., Rom 1:32; 5:12-21; 6:21-23; 7:5-24; 8:2-6; 2 Cor 2:16; 7:10).
As Joseph Fitzmyer wrote in his excellent commentary on Romans, showing that Paul is speaking of spiritual death:
13. If you live indeed according to the flesh, you will die. I.e., it is still possible for even justified Christians to conduct themselves as self-oriented and flesh-guided individuals; such persons will not escape condemnation to death, which is the “wages of sin” (6:23; cf. 8:6). Paul does not use the simple fut., but mellete apothnēskein, “you are going to die, you are bound to die,” i.e., you must die, because that is the natural consequence of “flesh” dominated by sin and death (recall 8:6). (Joseph A. Fitzmyer, Romans: A New Translation with Introduction and Commentary [AB33; New Haven: Yale University Press, 2008], 492)
