With what does the call to Islam begin: the call to tawhid (the oneness of Allah) or the call to prayer?

Question:
A questioner says: If a student of knowledge is in an Islamic country where there is shirk (associating partners with Allah), but when he calls to tawhid he faces problems with the people of the country because they do not love tawhid and prefer that he call them to prayer, should he start with prayer and then, after winning their hearts, call them to tawhid?

Answer:
Prayer is not valid in the presence of shirk. How can he call to something that is not valid?
Prayer is not valid in the presence of shirk (associating partners with Allah), so one begins by forbidding shirk and is patient with what befalls him, because he is in the path of Allah. However, he supplicates: . As for beginning with prayer and leaving shirk, no, this is contrary to the calling of the Prophets (peace and blessings be upon them). The Prophets began by forbidding shirk before they commanded prayer and other acts of worship. But he must use the lawful methods of da'wah (calling others to Islam); he does not use violence, harshness, or repulsion, but rather what Allah commanded: . This is the path of da'wah. Yes.