Will God allow such disobedience and apostasy to go unpunished?

#HC10

Certainly not. He is terribly displeased with our original sin as well as our actual sins. Therefore He will punish them by a just judgment both now and eternally, as He has declared: Cursed be every one who does not abide by all things written in the book of the law, and do them (Galatians 3:10).

Proofs

Certainly not. He is terribly displeased with our original sin as well as our actual sins. Therefore He will punish them by a just judgment both now and eternally, (Exodus 34:7; Psalm 5:4–6; Psalm 7:10; Nahum 1:2; Romans 1:18; Romans 5:12; Ephesians 5:6; Hebrews 9:27)
as He has declared: (Deuteronomy 27:26)
Cursed be every one who does not abide by all things written in the book of the law, and do them (Galatians 3:10).