Undoubtedly, Islamic organizations are responsible for calling to Allah's Way and uniting the Muslims' word. Each foundation then should exert all efforts for Da`wah, directing people to goodness, and sending Du`ah (callers to Islam) to possible regions to convey the message of Allah each foundation goes up to its capacity, as Allah (Exalted be He) says:
So keep your duty to Allâh and fear Him as much as you can
Allâh burdens not a person beyond his scope.
Say (O Muhammad ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭ ﺳـﻠﻢ): "This is my way; I invite unto Allâh (i.e. to the Oneness of Allâh Islâmic Monotheism) with sure knowledge, I and whosoever follows me (also must invite others to Allâh i.e. to the Oneness of Allâh Islâmic Monotheism with sure knowledge).
And who is better in speech than he who [says: "My Lord is Allâh (believes in His Oneness)," and then stands firm (acts upon His Order), and] invites (men) to Allâh's (Islâmic Monotheism), and does righteous deeds, and says: "I am one of the Muslims."
Invite (mankind, O Muhammad ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭ ﺳﻠﻢ) to the Way of your Lord (i.e. Islâm) with wisdom (i.e. with the Divine Revelation and the Qur'ân) and fair preaching, and argue with them in a way that is better.
Wisdom here refers to having knowledge of the instructions as stated by Allah (Exalted be He) and His Messenger (peace be upon him) while fair preaching is arousal of interests and threatening (against what is bad), guiding to goodness, and telling the good end of the pious and the bad end of the Kafir (disbeliever) or whoever disobeys Allah (Exalted be He). In addition, argument which is mentioned in the concerned Ayah (Qur'anic verse) is that which is supported by Shar`y (Islamic legal) proofs and conveyed in decent wording with neither violence nor severity. Nay, such argument is based on clear and soft explanation so that doubtful concepts, if any, are removed. It is worth mentioning that when a foundation carries out the foregoing duty, all those who are in charge of it are rewarded abundantly by Allah for whoever guides a person to anything that is good will receive the same reward as that of its doer as the Prophet (peace be upon him) said:
Whoever guides to something good has a reward similar to that of its doer.