Fatwa of Sheikh Ibn Bāz raḥimahullāh.

Question: I used to visit the people of good and the ’Ulamā' and the Mashāyikh, but sometimes I visited the homes of people of bid’ah, and my intention for that was to call them to the path of happiness and to the path of the Sunnah. Is there any sin in this? Answer: In the name of Allāh, The Most Merciful, Bestower of Mercy. All praises belong to Allāh, and praise and peace be upon the Messenger of Allāh and upon his family and companions and whoever follow his guidance. As for what follows, visiting the people of knowledge and Imān from Ahul-Sunnah wal Jamā’ah and visiting the brothers for Allāh's sake is Qurbah (an act of worship which draws a person closer to Allāh) and obedience. As for visiting the people of innovation, then visiting them is not permissible if done out of socialising and showing love and the likes of these. But if a student of knowledge visited them to give a sermon and remind and warn from the bid’ah, this is (something that is) thanked and rewarded because this is from the matter of inviting to Allāh and from the matter of ordering good and forbidding evil. So if you visited those who have with them something of innovation, you visited them to invite to Allāh and advise and direct, then you are rewarded, and it is a must that you do not leave that if there was any benefit. But if they continued (upon innovation) and did not respond (to the advice) then leave them. Source: https://binbaz.org.sa/fatwas/13707/%D8%AD%D9%83%D9%85-%D8%B2%D9%8A%D8%A7%D8%B1%D8%A9-%D8%A7%D9%87%D9%84-%D8%A7%D9%84%D8%A8%D8%AF%D8%B9-%D9%85%D9%86-%D8%A7%D8%AC%D9%84-%D8%AF%D8%B9%D9%88%D8%AA%D9%87%D9%85