Is the statement, "If God is great in your eyes, do not speak ill and backbite," considered an act of disbelief that necessitates re-embracing Islam?

The supplication using the phrase "O Allah, answer my prayer, even if it's just once" is reprehensible due to its ill manners, bad assumption about Allah, and belittling of His bounty. A Muslim should be resolute in supplication, as the Prophet, peace and blessings be upon him, said: "None of you should say: 'O Allah, forgive me if You wish,' or 'O Allah, have mercy on me if You wish.' Rather, he should be firm in his request, for there is no one who can compel Allah." This supplication and the statement "If Allah is great in your eyes, you wouldn't speak like that" are not disbelief. You should turn away from these whispers.