The Imam in our mosque in few days ago in the khutaba of Jumma Called prophet Hazrat Muhammad (Sm) as father(ruhani or other sense) of us(not father of Muslim). Can we call Nabiji as our father although we know he called us ( ummah) as brother in one of hadith in Musnade Ahmad? In Tableegh Jammat it has said that if any one goes out in the way of Allah, his every good(nek) amal will be turns into 49 crore(490 million) good amal;is it right or proved by authentic hadith?

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.

There is nothing wrong with saying that the Prophet is a father for the Muslims. The Prophet said: “I am to you like a father; I teach you.” [Abu Daawood - Al-Albaani graded it Hasan (good)]

Al-Munaawi said in his commentary on this Hadeeth: “i.e. I am to you like a father in love and compassion and not in rank and superiority, and like a father  in teaching you the matters that you must learn. As a father teaches moral conduct to his child, I am teaching you your rights and obligations.”

Shaykh Ibn Taymiyyah said in the book entitled Minhaaj As-Sunnah An-Nabawiyyah: “Allaah says (what means): {The Prophet is more worthy of the believers than themselves, and his wives are [in the position of] their mothers.}[Quran 33:6] According to a recitation of Ubayy: {…and he is their father}. Also, the famous recitation indicates this meaning, as the wives of the Prophet were the mothers of the believers because he [the Prophet] was the father of the believers. Had he not been like a father of the believers, his wives would not have been like their mothers.”

Therefore, the Prophet was a father in this regard and not a father by family lineage, as this kind of paternity is denied; Allaah says (what means): {Muhammad is not the father of [any] one of your men, but [he is] the Messenger of Allaah and seal [i.e. last] of the prophets. And ever is Allaah, of all things, Knowing.}[Quran 33:40]

Nevertheless, the paternity that is mentioned does not contradict the fact that he is a brother for the believers; Allaah says (what means): {The believers are but brothers, so make settlement between your brothers. And fear Allaah that you may receive mercy.}[Quran 49:10]

As regards the Hadeeth which you mentioned in the question, it was reported by Muslim, Ahmad and Ibn Maajah on the authority of Abu Hurayrah that the Prophet said: "... I wished we had seen our brothers.” They said: “Are we not your brothers, O Messenger of Allaah?" He replied: “You are my companions, and our brothers are those who have not yet come.”

Ibn Al-Qayyim said in Zaad Al-Ma’aad: “The Companions have the trait of brotherhood along with the advantage of being companions (of the Prophet ), but his followers after them, are his brothers and not his companions.”

With regard to the word "spiritual father", it is a term used by the Christians and by the church, so one should avoid it as there are other good words that could be used instead.

Concerning the second part of your question, the amount of the reward could not be known except by revelation from the Book of Allaah or the authentic Sunnah. The statement that whoever goes out in the way of Allaah (i.e. to call people to Allaah with the Tableegh Jamaa’ah), a good deed of his will be multiplied up to 490 million times, is a groundless statement (there is no evidence to support it). Nonetheless, it should be mentioned that calling to Allaah has great virtues and benefits.

For more benefit on the advantages and disadvantages of the Tableegh Jamaa’ah, please refer to Fataawa 87749, 85078 and 85666.

Allaah Knows best.