How can we reconcile the fact that disbelief is the absence of fundamental commitment (such as not accepting the ruling that intoxicants are forbidden), with the Messenger's - peace and blessings be upon him - acceptance of some companions' Islam conditioned on certain terms, such as not paying zakat or not participating in jihad, given the impossibility of accepting Islam on a condition of disbelief?

The difference between a Muslim and one who wishes to embrace Islam is clear and distinct. One who desires to convert to Islam is first required to utter the two testimonies (Shahadatayn), and his conversion becomes valid thereby, even if he stipulates invalid conditions. Then, after uttering the two testimonies and entering Islam, he is commanded to observe the rest of the Islamic laws.

The Prophet, peace and blessings be upon him, would accept from anyone who came to him desiring to embrace Islam the two testimonies only, and thereby protect his blood and render him a Muslim. He did not stipulate that they adhere to all Islamic laws before entering Islam. This is supported by his acceptance of the conversion of Thaqif on the condition that they would not be required to pay sadaqah (charity) or perform jihad (struggle), and the conversion of a man on the condition that he would only pray two prayers. Imam Ahmad adopted these hadiths and said: Islam is valid even with an invalid condition, and then one is obligated to observe all Islamic laws.

A Muslim does not become an unbeliever merely by committing sins and transgressions, unless he deems forbidden things lawful or denies the obligatory nature of the prescribed duties.