A Da`y is rewarded for good intention in Ijtihad even if he is wrong

Q 2: It is authentically reported on the authority of Abu Hurayrah and `Amr ibn Al-`As (may Allah be pleased with them both) that the Prophet (peace be upon him) said: If a judge gives a verdict according to the best of his knowledge and his verdict is correct (i.e. agrees with Allah and His Messenger’s verdict) he will receive a double reward, and if he gives a verdict according to the best of his knowledge and his verdict is wrong, (i.e. against that of Allah and His Messenger) even then he will get one reward. Does the judgment referred to here apply specifically to those in authority and judges? Or, is it general enough to include seekers after religious knowledge and scholars who make use of the best of their knowledge to choose the way of Da`wah (call to Islam) adequate to their countries that may turn out later to be right or wrong? Are they entitled to apply their personal judgments to such matters? Or, may they only adopt the opinions of reverend trustworthy scholars known for their knowledge and excellence?

A: The purport of the Hadith is general enough to include both the judge who decides on disputes and the Mujtahid (a scholar qualified to exercise juristic effort to infer expert legal rulings) provided that both of them have the qualifications of Ijtihad (exercising personal judgment) provided for by scholars of Usul-ul-Fiqh (principles of Islamic jurisprudence). The same applies to Da`ys (callers to Allah) who must be qualified to practice Ijtihad. Practicing their Da`wah, they should follow what Allah has mentioned in (Part No. 12; Page No. 266) the Ayah (Qur'anic verse) that reads: Invite (mankind, O Muhammad صلى الله 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 the Ayah that reads: Say (O Muhammad صلى الله عليه و سلم): "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 Glorified and Exalted be Allâh (above all that they associate as partners with Him). And I am not of the Mushrikûn (polytheists, pagans, idolaters and disbelievers in the Oneness of Allâh; those who worship others along with Allâh or set up rivals or partners to Allâh)." Moreover, they have to apply and put into practice the methods adopted by the Prophet (peace be upon him) while calling people to Islam and put aside all other methods innovated by people.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.