Beginning the call to tawhid (the oneness of Allah) before denouncing sins

Question:
A questioner says: Is it permissible for a da'iyah (caller to Islam) in these days to attend the gatherings and parties of disbelievers, where there is tabarruj (a woman's display of her adornment) and drinking of khamr (intoxicants), on the pretext of calling to Allah, arguing that the Prophet (peace and blessings be upon him) used to attend the gatherings of the mushrikin (those who associate partners with Allah) and call them?

Answer:
This issue regarding khamr (intoxicants) and the issue of exposing oneself are two separate matters. But the issue of kufr (disbelief) is that he calls them to tawhid (the oneness of Allah) and to singling out Allah in worship first. If they accept that, then he forbids them from khamr (intoxicants), from exposing themselves, and so on. Yes.