Is it possible to sin in heaven?
No. Scripture states, "Nothing unclean shall enter [heaven], nor any one who practices abomination or falsehood, but only those who are written in the Lamb's book of life" (Rev. 21:27). When the soul enters into the direct presence of God, it is impossible to sin. The inability to sin in heaven is not a negation of free will but is a result of the will having been purified and fully conformed to the will of God.