What is the superiority and excellence of the Imaam over those he leads in prayer?
All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Leading the prayer has its own virtues and merits. The Imaam who leads worshippers in the congregational prayer properly and as due (i.e. fulfilling all its due conditions and pillars) will earn great rewards in return. The Prophet, sallallaahu ‘alayhi wa sallam, and the rightly guided caliphs favored assuming the role of leading the prayers over calling the Athaan and they only favor what is better (i.e. in terms of rewards and virtues). The role of the Imaam should be shouldered by the best among all the worshippers. Therefore, most Muslim jurists believed that leading the prayer is better than calling the Athaan. As for the rewards of the Imaam and the Ma'mumeen (i.e. the ones being led in prayer), they share them for performing the congregational prayer. Imaam Al-‘Iz ibn ‘Abdus-Salaam said in his book, Qawaa‘id Al-Ahkaam, "Some scholars favored leading the prayer (over calling the Athaan) as leading the prayer results in benefiting both the Imaam and the Ma'mumeen in terms of earning rewards. The Imaam earns the rewards for performing the congregational prayer and causes the Ma'mumeen to earn such rewards as well and, hence, he gains the like of their rewards. The prayer that is performed in congregation is superior to that which is performed individually by twenty-five or twenty-seven times as was reported in the Hadeeth. Nothing similar was reported in the Sunnah with regards to the Athaan. The question is, 'Will the Ma'mumeen be rewarded for offering the Imaam the chance to lead them in the prayer and consequently earn such great rewards and attain such a refined status?' The answer is, 'Yes, they will.' The Prophet, sallallaahu ‘alayhi wa sallam, said: 'Who will give charity to him by praying with him (in congregation)?'"
You can search for fatwa through many choices