Never

Young men, when did God ever fail to keep His word? Never.

What He has said, He has always done; and what He has spoken, He has always made good. Did He fail to keep His word at the flood? No. Did he fail with Sodom and Gomorrah? No. Did He fail with with unbelieving Jerusalem? No. Has He failed with the Jews up to this very hour? No. He has never failed to fulfill His word. Take care, lest you be found amongst those by whom God's Word is despised.

Never laugh at religion. Never make a jest of sacred things. Never mock those who are serious and in earnest about their souls. The time may come when you will count those happy whom you laughed at--a time when your laughter will be turned into sorrow, and your mockery into heaviness.

J.C. Ryle in Thoughts for Young Men