The noble Shaikh, Sālih Ibn ‘Abdul-‘Azīz Ālush-Shaikh said: “One of the callers to Islam wrote a letter to my grandfather, the eminent scholar, Muhammad Ibn Ibrāheem Ālush-Shaikh (رحمه الله) which included the following: “I am going to India for the purpose of da’wah. If they see me raising my voice with the āmeen in Prayer, and raising my hands in other than the opening takbeer of the Prayer, and placing my right hand over my left [on the chest], they will say: ‘This is a Wahābī’ and perhaps they will not listen to what I have to say, and perhaps they will not allow me to speak in their Mosques [in order to call them to the truth].”
The response of Shaikh Muhammad Ibn Ibrāheem (رحمه الله) was: “If you anticipate that by leaving off these Sunan (non-obligatory acts) in front of them [helps] you to call them to the Tawheed of Allāh, the Mighty and Majestic, and to the great affairs of Sunan, then that is obligatory upon you, that you leave off the optional Sunnah for that which is a greater obligation. However if you do not anticipate that, then do not leave off [anything from] the Sunnah.
And this is what is necessitated upon the caller [to Islam] to carry out, because he advances the people to that which is greater in importance.
To leave off some affairs so as to attain that which is more important is something desirable – but if you were to dispute over every issue, you would lose out on setting aright the understanding of the people in the matters of immense importance.”
Source: At-Tareeq Ilan-Nubooghil-‘Ilmī of Shaikh Sālih Ibn ‘Abdul-‘Azeez Ibn Muhammad Ibn Ibrāheem Ālish-Shaikh, pp. 90-91.
Shaikh Muhammad Ibn Ibraheem is the former Mufti of Saudi Arabia (b. 1893, d. 1969) and a descendant of Shaikhul-Islam Muhammad Ibn Abdul-Wahhāb (رحمه الله). He was the Mufti of the Kingdom from 1953 till his death in 1969, may Allah have mercy upon him.
Shaikh Sālih Ibn ‘Abdul-‘Azeez is the “Minister of Islamic Affairs, Call and Guidance” (Wazeer ash-Shu’oon al-Islāmiyyah wad-Da’wah wal-Irshād) of Saudi Arabia, since 1996 till present. He is the grandson of the Mufti, Shaikh Muhammad Ibn Ibraheem.
Compare this scholarly answer to those who spend hours in public debates in front of large audiences arguing with the worshippers of graves over the obligation of raf’al-yadayn (raising the hands) and reciting Al-Fātihah behind the imām in the prayer!
Additionally, the purpose of entering their mosques is to call them to Tawheed and to the importance of the Sunnah, not to relegate these tremendous affairs in favour of political goals and futile calls to unity upon other than the Sunnah. The rectification of the matters of belief and methodology (the ‘aqeedah and manhaj) is starting point of the caller to Allah. The proof is in the saying of Allah: “Verily, We sent a Messenger to every nation, calling them to the worship of Allah, and to shun the false deities.” And His (the Most High) saying: “Follow that which has been revealed to you from your Lord, and do not follow other than that from allies and protectors, little is it that you remember.” And His (the Most High) saying: “Say O Prophet to the people: If you truly love Allah, then follow me, then Allah will love you and forgive you your sins.”