1 Bible Verses about Apostasy in OT

To use the words of Scripture-- 'If to-day you hear God's voice, harden not your hearts, as when Israel provoked me.' Who were they who heard God speak and yet provoked him? Were not they all those who left Egypt under the leadership of Moses? And with whom was it that God was sorely vexed for forty years? Was not it with those who had sinned, and who fell dead in the desert?read more.
And who were they to whom God swore that they should not enter upon his rest, if not those who had proved faithless? We see, then, that they failed to enter upon it because of their want of faith.