How do I convince my unbelieving neighbor of the Oneness of Allah, the Mighty and Exalted?

The most effective way to convince a disbeliever of Allah's Oneness (Tawhid) is the method of the Holy Quran, which begins by affirming the Oneness of Lordship (Tawhid al-Rububiyyah), then moves to the Oneness of Godhead (Tawhid al-Uluhiyyah), employing rational arguments as in His (Allah's) saying: "Allah has not taken any son, nor has there ever been with Him any deity. [If there had been], then each deity would have taken what it created, and some of them would have risen over others. Exalted is Allah above what they describe."

Among other means are: demonstrating the greatness of Islam and its legislations, the biography of the Prophet (peace and blessings be upon him) and his miracles, and the stance of Muslims towards previous prophets, in addition to explaining the deviance and distortion of other religions. The Muslim must be armed with knowledge and firm faith when engaging in dialogue.