Hadrat Ibn Umar Radiallahu Anhu narrates that Rasulullah Sallallahu Alaihi Wasallam said: “Salaah offered in congregation is 27 times superior to Salaah offered individually.” [Sahih Bukhari]
Hadrat Abu Hurairah Radiallahu Anhu narrates that Rasulullah Salallahu Alaihi Wasallam said: “The Salaah of a person offered in congregation is 25 times superior to his Salaah offered in his house and in his business place. This is because when he performs a perfect Wudhu and then proceeds to the Masjid-solely for the purpose of Salaah-then for every step he takes, he is elevated by one rank and one sin is wiped off him. Then, when he offers his Salaah, the angels continue praying for him for as long as he remains in his place of Salaah. The angels say, ‘O Allah! Send salutations on him, O Allah, have mercy on him!’ And you are considered to be already in Salaah as long as you remain waiting for the Salaah (in congregation to commence).”
Another narration states that the angels pray, ‘O Allah! Forgive him. O Allah! Relent to him.” They continue praying as long as he does not harm anyone and as long as he does not commit any evil therein. [Sahih Bukhari]
Hadrat Ibn Masood Radiallahu Anhu narrates: “Whoever would like to meet Allah Ta’ala tomorrow as a Muslim, should safeguard these Salaahs where the call for them is made (in the Masjid). Surely Allah Ta’ala prescribed for your Nabi Sallallahu Alaihi Wasallam the ways of guidance. And these Salaahs are from among the ways of guidance. If you were to offer them in your houses as this person who remains behind offers them in his house, you would be abandoning the Sunnah of your Rasul Sallallahu Alaihi Wasallam. And if you abandon the Sunnah of your Rasul Sallallahu Alaihi Wasallam, then you will certainly go astray. A person who performs Wudhu beautifully and then goes to the Masjid, Allah Ta’ala certainly records a good deed for every step that he takes, raises his rank by one, and wipes out one sin from him. I remember when none from among us (the Sahaaba) would abstain from Salaah in congregation except a hypocrite whose hypocrisy was well-known. I also remember when a person would be brought up (to the Masjid) while taking support between two people until he was made to stand in the row (the Saff of Salaah).” The words, “taking support between two people” mean that he is helped on either side i.e. they hold him by his underarms and walk him to the Masjid.
The following is related in another narration: “Surely Rasulullah Salallahu Alaihi Wasallam taught us the ways of guidance. One of the ways of guidance is offering Salaah in the Masjid in which the Adhaan is called.” [Sahih Muslim]
Hadrat Ubay ibn Ka’ab Radiallahu Anhu narrates: “One day, Rasulullah Sallallahu Alaihi Wasallam performed the Fajr Salaah for us. He then asked, ‘Is so and so person present?’ The Sahaaba replied, ‘No.’ He then asked, ‘Is so and so person present?’ The Sahaaba replied, ‘No.’ He said, ‘Surely these two Salaahs are the most difficult on the hypocrites. If you all only knew the reward for these two Salaahs, you would attend them even if you had to crawl on your knees.
Surely the first row is like the row of angels. Had you known the virtue of it, you would have hastened towards it. A person offering Salaah with another person is purer than his offering it alone. His Salaah with two people is purer than offering it with one person. The more the number of people offering Salaah together, the more beloved it is to Allah Ta’ala.” [Musnad Ahmad]