Defile from the Strong's Greek/Hebrew dictionary
de·file1 5351 phtheiro (fthi'-ro);
probably strengthened from phthio (to pine or waste); properly, to shrivel or wither, i.e. to spoil (by any process) or (generally) to ruin (especially figuratively, by moral influences, to deprave):
KJV-- corrupt (self), defile, destroy.
1 Corinthians 3:16-17
of God through the Spirit, <Eph. 2:22>. Every Christian is a living temple of the living God. God dwelt in the Jewish temple, took possession of it, and resided in it, by that glorious cloud that was the token of his presence with that people. So Christ by his Spirit dwells in all true believers. The temple was devoted and consecrated to God, and set apart from every common to a holy use, to the immediate service of God. So all Christians are separated from common uses, and set apart for God and his service. They are sacred to him-- a very good argument this against all fleshly lusts, and all doctrines that give countenance to them. If we are the temples of God, we must do nothing that shall alienate ourselves from him, or corrupt and pollute ourselves, and thereby unfit ourselves for his use; and we must hearken to no doctrine nor doctor that would seduce us to any such practices. Note, Christians are holy by profession, and should be pure and clean both in heart and conversation. We should heartily abhor, and carefully avoid, what will defile God's temple, and prostitute what ought to be sacred to him.
(from Matthew Henry's Commentary)
1 Corinthians 3:16
Theos (grk 2316). If any man destroy the temple of God, him will God destroy. The verb is the same in both clauses. If any man injure, corrupt, or destroy the church of God by false doctrine, God will destroy him-- will take away his part out of the book of life. This refers to him who willfully opposes the truth; the erring, mistaken man shall barely escape; but the obstinate opposer shall be destroyed. The former shall be treated leniently; the latter shall have judgment without mercy.
(from Adam Clarke Commentary)
A third argument is the honour already put on them: Know you not that your bodies are the members of Christ? If the soul be united to Christ by faith, the whole man is become a member of his mystical body. The body is in union with Christ as well as the soul. How honourable is this to the Christian! His very flesh is a part of the mystical body of Christ. Note, It is good to know in what honourable relations we stand, that we may endeavour to become them. But now,
(from Matthew Henry's Commentary)