en_tn/heb/03/12.md

evil heart of unbelief in any of you

"an evil, unbelieving heart in any of you" or "an unbelieving heart that leads any of you to do evil" (See: rc://en/ta/man/translate/figs-hendiadys)

a heart that will turn away

"a heart that will turn you away." AT, starting a new sentence: "Do not turn away."

the living God

Possible meanings: 1) "the true God who is really alive" (see UDB) or 2) "the God who gives life."

so long as it is called today

while there is still opportunity

no one among you may be hardened by the deceitfulness of sin

"become stubborn, allow others to deceive you, and commit sins" (see UDB) or "you do not commit sins, deceive yourselves, and become stubborn" (See: rc://en/ta/man/translate/figs-personification)