This is true but David paid a very high price for his sin, his life was full of tragedy and vexation thereafter ... and this is the answer to people who sin wilfully against grace..
The letter to Hebrews was addressed to folks whose association with God is
governed by the covenant that Moses' people entered into with God per
Exodus, Leviticus, Numbers, and Deuteronomy; wherein is stated:
"But the person, be he citizen or stranger, who acts defiantly reviles the
Lord; that person shall be cut off from among his people. Because he has
spurned the word of the Lord and violated His commandment, that person
shall be cut off-- he bears his guilt. (Num 15:30-31)
There are no atonements in the Levitical system for scofflaws; and yet
David was one of those very kinds of offenders in his premeditated sins of
adultery and murder with Bathsheba. Where's David today; in Hell? No, he's
not in Hell because God wiped David's criminal history by transferring his
willful sins to the cross. (Isa 53:6, Rom 3:23-26, Acts 13:38-39)
_