Meaning of statement: the worst Muslim is better than the best non-Muslim
20-3-2016 | IslamWeb
Question:
Assalaamu alaykum dear respected Shaykh. Could you please explain the following statement: "The worst Muslim is better than the best disbeliever."
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad 
is His slave and Messenger.
What is meant by this statement is that the Muslim and non-Muslim are not equal. Allaah clarified this in the Quran, as He says (what means): {Then will We treat the Muslims like the criminals? What is [the matter] with you? How do you judge?} [Quran 68:35-36]
No matter how wrong a Muslim is, he is still in the circle of Islam unless he apostates. A non-Muslim, no matter how good he is, is still in the circle of disbelief unless he embraces Islam and utters the Two Testimonies of Faith. The good deed of Tawheed (pure monotheism) is not equaled by any good deed that a non-Muslim does. The bad deed of disbelief is not equaled by any bad deed done by a Muslim.
On the other hand, a Muslim has the right of alliance upon his other fellow Muslim. If he commits a sin, he is hated according to the degree of that sin, but a non-Muslim is absolutely hated. Nevertheless, this does not prevent from being kind to him. The sharee'ah permits that a Muslim be kind to a non-belligerent non-Muslim; Allaah says (what means): {Allaah does not forbid you from those who do not fight you because of religion and do not expel you from your homes - from being righteous toward them and acting justly toward them. Indeed, Allaah loves those who act justly.} [Quran 60:8]
Moreover, Asmaa’ bint Abu Bakr 
reported, “My mother came to me during the lifetime of the Messenger of Allaah, and she was a polytheist. I said to the Messenger of Allaah (seeking his verdict), “My mother has come to me and she desires to receive a gift from me, shall I keep good relations with her?” The Prophet said, “Yes, keep good relations with your mother.” [Al-Bukhari and Muslim]
Indeed, this may encourage them and be a reason for them to embrace Islam. For more benefit, please refer to fataawa 1234 and 81627.
Allaah knows best.