1 Bible Verses about Apostasy in OT

we hold fast the beginning of our confidence firm to the end) While it is said; To-day, if ye will hear his voice, harden not your hearts, as in the provocation. For who, when they had heard, provoked God? Were they not all that came out of Egypt by Moses? And with whom was he grieved forty years? Was it not with them who had sinned?read more.
Whose carcases fell in the wilderness? And to whom sware he, that they should not enter into his rest, but to them that believed not? So we see, they could not enter in, because of unbelief.