Is the profaning of God’s name ... so grievous a sin that His wrath is kindled against those also who do not help ... to hinder and forbid it?

Heidelberg Catechism

Question 100. Is the profaning of God’s name, by swearing and cursing, so grievous a sin that His wrath is kindled against those also who do not help as much as they can to hinder and forbid it?

Answer. Yes, truly,[1] for no sin is greater and more provoking to God than the profaning of His name; wherefore He even commanded it to be punished with death.[2]

[1] Lev 5:1; [2] Lev 19:12, 24:15-16; Prov 29:24-25