The propagation of Islam was the mission of all the prophets and messengers of Allah. There was never a prophet who was not a preacher and teacher. They all preached the same message: ‘Worship Allah, you have no other god but Him.’ They all called to their people, saying: ‘I do not seek any reward from you for this work.’
There are five premises to the Islamic call, it has five approaches, and its results are also five.

The five premises
First: sincerity and truthfulness with Allah, and to seek His favor. Allah says: ‘And, they were not enjoined aught but that they should worship God, sincere in their faith to Him alone.’ (98:5)

The Prophet (peace be upon him) foretold that the first with whom the fire of hell will be lit are three; among them a scholar who acquired knowledge so that people would say he is learned.

Second: to practice what one preaches. It is a scandal and disgrace that a person’s actions contradict his words. Allah derides such people in His Quran: ‘Do you bid other people to be pious, the while you forget your own selves – and yet you recite the divine writ? Will you not, then, use your reason?’ (Qur’an 2:44)

Third: gentleness in presenting the message. Allah advised Musa and Haroon (peace be upon them both) to adopt this measure with Pharaoh, the greatest tyrant of his time: ‘But speak unto him in a mild manner, so that he might bethink himself or [at least] be filled with apprehension.’ (Qur’an 20:44)

And to Prophet Muhammad, He also cautioned: ‘And it was by God’s grace that thou [O Prophet] didst deal gently with thy followers; for if thou hadst been harsh and hard of heart, they would indeed have broken away from thee’ (Qur’an 3:159).

Hence, it was on this basis the Prophet, declared: ‘Make matters easy and do not make them difficult. Give glad tidings and do not drive people away.’

Fourth: adopt a gradual approach to propagation. Do as Prophet Muhammad (PBUH) did in his mission by beginning with the most important matters; then follow them up in order of priority. This was clearly demonstrated in the advice he gave to Muadh (may Allah be pleased with him) before he sent him to Yemen. “You will come upon a People of the Book (Jews and Christians), the first thing you should invite them to is to bear witness that there is no God except Allah and that I am the Messenger of Allah. If they respond positively to this, then inform them that Allah had ordained for them five prayers each day and night.”

Fifth: address every person with what is suited for them and their needs. There is a special approach to the people of the cities and another approach to the villagers. Similarly, there is a special approach to the Bedouin. The intellectual has his position and the ignorant has his position. So, too, there is a style for the argumentative and an entirely different one for the submissive. ‘And whoever is granted wisdom has indeed been granted wealth abundant.’

The five means of propagation
First: the individual method; that is, to invite the person individually if the matter pertains to him specifically.
Second: public or mass propagation, such as in lectures or exhortations that benefit the generality of people.
Third: private lessons to students each in his specialty. This is the task of the scholars who specialize in their disciplines.
Fourth: propagation through writing, correspondence, and authorship with guidance and benefit for those who are called.
Fifth: propagation using modern means of communication to advance the cause of truth or any means within your own individual capacity.

Compiled From:
“Thirty Lessons For Those Who Fast” – A’id Abdullah al-Qarnee