The Prophet (saas) warned and reminded people in such a way as to influence their conscience

the prophet (saas) spent all his life, once the qur'an had been revealed to him, calling people to the religion and guiding them to the true path. in one verse, allah tells the prophet (saas) how he should address people:

say: "this is my way. i call to allah with inner sight, i and all who follow me. glory be to allah! i am not one of those who associate others with him." (surah yusuf: 108)

as can be seen from the verses of the qur'an, the prophet (saas) encountered a number of difficulties when warning people and teaching them about the qur'an and true morality. since not everyone was on the true path, people made life difficult for the prophet (saas), out of jealousy, hatred and envy. some were slow to understand his words and dragged their feet when they did so, some behaved hypocritically, saying that they believed his words when they really did not. the prophet (saas) continued to explain the religion with great determination, paying no heed to all those obstacles. such people's attitudes are revealed in a verse:

… you believe in all the books. when they meet you, they say, "we believe." but when they leave they bite their fingers out of rage against you. say, "die in your rage." allah knows what your hearts contain. (surah al 'imran: 119)

another verse discusses the prophet (saas)'s determination in the face of those who opposed him:

those to whom we gave the book rejoice at what has been sent down to you but some of the parties refuse to acknowledge part of it. say: "i have only been ordered to worship allah and not to associate anything with him. i summon to him and to him i will return." (surat ar-ra'd: 36)

the prophet (saas) continued to warn those who would not believe, and to use the most effective way of talking about the religion, in the hope they would find faith and abandon their hatred of him and his religion. the attitude displayed by those people in the face of what he had to say is described in surat an-nisa':

do you not see those who claim that they believe in what has been sent down to you and what was sent down before you, still desiring to turn to a satanic source for judgement in spite of being ordered to reject it? satan wants to misguide them far away. when they are told, "come to what allah has sent down and to the messenger," you see the hypocrites turning away from you completely. (surat an-nisa': 60-61)

despite the two-faced behavior of those who opposed him, the prophet (saas) spoke to them in terms that would enable them to see the truth and which would work on their consciences. one verse reads:

allah knows what is in such people's hearts so turn away from them and warn them and speak to them with words that take effect. (surat an-nisa': 63)

it was of course a heavy responsibility to give advice to his enemies, to show them the error of their ways and to call them to the true path. yet, for someone who, like the prophet (saas), has put his trust in allah, who knows that faith is a gift from him, and fears allah alone, and not anyone else, allah will provide assistance and support.

say: 'this is my way. i call to allah with inner sight, i and all who follow me. glory be to allah! i am not of those who associate others with him!'
(surah yusuf: 108)

in several verses of the qur'an, allah reveals that he has sent messengers in order to turn those who have strayed back to the true path, to purify them, and to teach them the holy verses. as we have seen above, throughout his life, the prophet (saas) persevered in the responsibility that allah had laid on him with great patience, fortitude and determination. even in the final sermon that he gave, very shortly before dying, he continued to teach and instruct muslims.

allah sets out these beautiful responsibilities in a number of verses:

for this we sent a messenger to you from among you to recite our signs to you and purify you and teach you the book and wisdom and teach you things you did not know before. (surat al-baqara: 151)

allah showed great kindness to the believers when he sent a messenger to them from among themselves to recite his signs to them and purify them and teach them the book and wisdom, even though before that they were clearly misguided. (surah al 'imran: 164)

it is he who raised up among the ummi a messenger from them to recite his signs to them and purify them and teach them the book and wisdom, even though before that they were clearly misguided. (surat al-jumu'a: 2)

in one verse, allah describes the prophet (saas)'s advice and warnings as "things that will bring one to life":

you who believe! respond to allah and to the messenger when he calls you to what will bring you to life! know that allah intervenes between a man and his heart and that you will be gathered to him. (surat al-anfal: 24)

that is why the prophet (saas)'s advice and exhortations are unlike those of anyone else. abiding by these warnings is a means of salvation in this world and the next. each of the prophet (saas)'s exhortations are founded on wisdom that will save people from evil, cruelty, pessimism and suffering. since all his advice is inspired and assured by allah, a sincere muslim will surrender himself to them and find faith.

the words of the prophet (saas) that have come down to us contain the excellent advice he gave to the faithful. one example is the advice he gave to his companion muadh. it is reported that he spoke thus:

"o muadh, i advise you: fear allah, speak the truth, fulfil promise, pay up trust, give up breach of trust, save your neighbour, show kindness to orphans, be modest in talk, spread peace, do good deeds, stick to faith, earn knowledge about the qur'an, love the next world, fear rendering of accounts...

o muadh, i forbid you: don't tell a truthful man liar, don't follow any sin, don't disobey a just judge, and don't create disorder in land.

o muadh, i give you instruction: fear allah while passing by each stone, tree, and heaps of earth. make repentance anew after committing any sin. repent secretly for secret sin and openly for open sin."

17 that is how the prophet (saas) educated those close to him and muslims, and called on them to have good character.
allah is the protector of those who believe. he brings them out of the darkness into the light. but those who disbelieve have false gods as protectors. they take them from the light into the darkness. those are the companions of the fire remaining in it timelessly, for ever.
(surat al-baqara: 257)

do people imagine that they will be left to say, 'we believe,' and will not be tested? we tested those before them so that allah would know the truthful and would know the liars. or do those who do bad actions imagine they can outstrip us? how bad their judgement is!
(surat al-ankabut:2-4)