What should the da'iyah do regarding his culture?

Q: What should the da'iyah do regarding his culture? And from what should he derive it so that his da'wah is effective and answered, by the permission of Allah?

A: Indeed, calling people to Allah is among the most important matters and the greatest of obligations, and people are in the greatest need of it, whether it is a Muslim community or a disbelieving community.
The Muslim society needs to be alerted to the errors and wrongs it may fall into, so that it may rectify what has occurred, so that it may stand firm in obedience to Allah and His Messenger, and so that it may cease from what Allah and His Messenger have forbidden. The disbeliever is called to Allah, and it is made clear to him that Allah created him to worship Him, and that it is obligatory upon him to enter into Islam and take upon himself what the Prophet of Guidance (peace and blessings be upon him) brought. However, the one who calls to Allah must observe important matters in his da'wah so that his da'wah is successful and its outcome is praiseworthy. The greatest and most important of these is knowledge; he must possess knowledge, and knowledge is only taken from the great Book of Allah and the Sunnah of His noble Messenger (peace and blessings be upon him). As He, the Exalted, said: [Yusuf: 108]. The scholars said its meaning is: "with knowledge," because knowledge in relation to known things is like sight in relation to visible things. Therefore, the scholar must know how to command, how to forbid, and how to call to Allah, like the one who has sight and sees before him what harms him, such as pits and thorns, and avoids them.
So the conclusion is that the one who calls to Allah must have the knowledge, insight, and Islamic culture derived from the Book of Allah and the Sunnah of His Messenger, upon whom be the best of prayers and blessings from his Lord, that enables him to guide people to good and warn them of evil. He should also make use of the books of scholars known for their uprightness, virtue, and sound creed, so that he is on clear insight regarding what he calls to and what he forbids.
Then there is another matter, which is that he should be careful in his da'wah and be gentle in it. If the one being called can respond without the need for admonition or argument that clarifies the truth with scriptural evidence and good manner, then if he accepts that, the matter is concluded and the objective is achieved.
And what is required in this is sincerity for Allah, and that he should beware of showing off (riya'). He should intend in his da'wah the Face of Allah and the Hereafter, not intending the praise of people or their attention, nor seeking any worldly display. He only wants the Face of Allah. For this reason, Allah, the Exalted, said: [An-Nahl: 125]. And He said: [Fussilat: 33]. And there is another matter, which is choosing appropriate words and being gentle in speech, and not being harsh except when there is a necessity for it, as Allah commanded in His saying, the Exalted and Majestic: [An-Nahl: 125]. And His saying, the Exalted: [Al-'Ankabut: 46]. And they are the disbelievers from among the Jews and the Christians: [Al-'Ankabut: 46].
So gentleness is necessary, as he (peace and blessings be upon him) said: . And he (peace and blessings be upon him) said: . So the Muslim should have gentleness and good manner in his da'wah so that he is answered, and so that he is not met with rejection or with a manner that does not suit him. For some people, due to their harshness and bad character, may be met with cursing and reviling, which only makes the mud stickier.
So when the one who calls to Allah has a good manner, is wise and gentle, he will not lack the acceptance of his da'wah, or at least good speech and a good response from the one being called, from whom it is hoped that through gentleness he will be affected by his da'wah and respond to it. And Allah is the One to be asked for help.