Quran 5:53 — The Feast (Al-Ma'edah)

The believers will then say, "Are these the same people who swore by GOD solemnly that they were with you?" Their works have been nullified; they are the losers.

[5:52] You will see those who harbor doubt in their hearts hasten to join them, saying, "We fear lest we may be defeated." May GOD bring victory, or a command from Him, that causes them to regret their secret thoughts.

[5:54] O you who believe, if you revert from your religion, then GOD will substitute in your place people whom He loves and who love Him. They will be kind with the believers, stern with the disbelievers, and will strive in the cause of GOD without fear of any blame. Such is GOD's blessing; He bestows it upon whomever He wills. GOD is Bounteous, Omniscient.