What is the ruling on one who claims that eating with a spoon is better than or equal to eating with three fingers, or that there is a method equal to or better than dipping a fly in a vessel, by analogy to the nullifiers of Islam regarding the belief in the existence of guidance better than or equal to the guidance of the Prophet (PBUH)?

It is not appropriate to prefer eating with a spoon over eating with one's hand, knowing that eating with one's hand is a Sunnah (definition). It is likewise not appropriate to prefer another method over dipping a fly in a drink if it falls into the vessel, knowing that this is a Sunnah. Whoever rejects this out of criticism and disparagement of the Prophet's Sunnah, peace and blessings be upon him, commits an act of disbelief (kufr). And whoever rejects it because it does not conform to the rules of experimental sciences, or because it is not intellectually accepted, is in grave danger.

As for believing that anything from the guidance of distorted religions or man-made laws is better and more righteous than the guidance of Muhammad, peace and blessings be upon him, this is disbelief (kufr) and an exit from the fold of Islam. This is because his law is complete, as Allah Almighty says: {This day I have perfected for you your religion and completed My favor upon you and have approved for you Islam as religion.} [Al-Ma'idah: 3], and because of his, peace and blessings be upon him, saying: "The best speech is the Book of Allah, and the best guidance is the guidance of Muhammad."