Charles Spurgeon Commentary Hebrews 3:12

"Take heed, brethren, lest haply there shall be in any one of you an evil heart of unbelief, in falling away from the living God:" — Hebrews 3:12 (ASV)

Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God.

That is the thing that provokes God – unbelief; not so much the unbelief of the head, as the unbelief of the heart, when the heart will not yield to the plan of salvation, when people want to be saved by their own works, or else are indifferent altogether about whether they are saved or not.

It is heart-unbelief that damns them. It is heart-faith that is the means of salvation. With the heart man believeth unto righteousness; but heart-unbelief leads to, and seals his ruin.