Shaykh Salih al-Fawzan explains that the spread of daʿwah comes through sincere intention. Check your motive—if you seek Allah’s ﷻ pleasure, not praise or fame, then your daʿwah is on the right path.
You mentioned that the reason for the spread of the Daʿwah of Shaykh Muḥammad ibn ʿAbd al-Wahhāb and its benefits was due to his sincerity. Therefore, how do we know that we have actualised it and we are receiving its result?
This is something that Allāh ﷻ places in you. If sincerity appears upon you and a righteous intention then this is what is intended. Look to your intention, is it an intention for Allāh ﷻ or is it is a intention for wealth, praise or the likes of that? It is said that “Your intention is your mount [riding beast]” and this is correct. Your intention is your mount [riding beast]. So look to your intention when calling to Allāh ﷻ, do you want praise, fame or position, then you won’t have any share [of reward] in the hereafter. If you want the face of Allāh ﷻ and you want sincerity for the sake of Allāh ﷻ and to make the worship free of shirk, then you are upon good.
