Bible Verses About Apostasy: Cautions against

Not forsaking the assembling of ourselves together, as the manner of some is; but exhorting one another: and so much the more, as ye see the day approaching.

Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils;

But we are not of them who draw back unto perdition; but of them that believe to the saving of the soul.

For if we sin wilfully after that we have received the knowledge of the truth, there remaineth no more sacrifice for sins,

For if after they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled therein, and overcome, the latter end is worse with them than the beginning.