Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God.
Take heed. To be joined with "Wherefore," Hebrews 3:7.
Lest there be, х estai (G2071)] - 'lest there shall be;' lest there be, as I fear there is; it is not merely a possible contingency, there is ground for thinking it will be so.
In any - `in any one of you.' Not merely all ought to be on their guard, but to be so concerned for each one as not to suffer any to perish through their negligence (Calvin).
Heart. The heart is not to be trusted. Compare Hebrews 3:10.
Unbelief - faithlessness. Christ is faithful; therefore, saith Paul to the Hebrews, we ought not to be faithless, as our fathers were under Moses.
Departing - apostatizing. The opposite of "come unto" Him (Hebrews 4:16). God punishes apostates in kind. He departs from them-the worst of woes (Hosea 9:12).
The living God - the exclusive characteristic of the God of Israel, not like the lifeless gods of the pagan; therefore One whose threats are awful realities. To apostatize from Christ is to apostatize from the living God (Hebrews 2:3).