How does a person begin to invite another person [to Islam] and with what does he speak to him?

The caller [to Islam] must invite to God with wisdom and good admonition and gentleness. He should start with what is most important, then the next important, just as the Prophet, peace and blessings be upon him, did with Mu'adh when he sent him to Yemen, by starting with the two testimonies of faith, then prayer, then zakat. The caller should seize the appropriate opportunities, time, and place to invite people to the truth.