The reward for going to the Musjid is equal to that of Hajj and Umrah

"It has been reported from Hadhrat Abu Umaamah (radhiallahuanhu) that Rasulullah (sallallahu alaihi wasallam) said, ' The person whoemerges from his home purified (i.e. With wudhu) and proceeds towards the Musjid for Fardh Salaat, then his reward is like that of one proceeding for Hajj. And the one who emerges from his home purified to go to the
Musjid for Chasht Salaat, is like one who performs Umrah (the condition being that besides Salaat there is no other motive for proceeding to Musjid)." [Hadith Ahmad / Mishkaat, page 70]

Fardh Salaat for men should as far as possible be performed in the Musjid with Jamaat. In fact, some Ulama, are so strict in their ruling that Fardh Salaat is not valid except in Jamaat. The Ahaadith extol many virtues of performing Fardh Salaat with Jamaat.

The angels make dua for the person proceeding towards the Musjid

“Hadhrat Abu Hurairah (radhiallahu anhu) reports that Rasulullah (sallallahu alayhi wasallam) said, ‘The Salaat of a man performed in congregation is 25 times more superior than his Salaat performed in his home or business. This is so when he performs a proper wudhu and proceeds towards the Musjid. He does not emerge except with the intention
of performing Salaat. He does not walk one step except that he is being raised by one stage and one of his sins are being forgiven. Whilst he is performing Salaat, the angels continuously supplicate for him thus: ‘O Allaah! Bless him and have mercy on him.’ They continue making dua for him as long as he awaits the (congregational) Salaat.”

In another narration it is reported that Nabi (sallallahu alaihi wasallam) said, “When he enters the Musjid, and remains engaged in Salaat, then the angels supplicate thus, ‘O Allaah! Forgive him, and accept his repentance.’ This continues as long as he does not harm anyone and remains in a state of wudhu.” [Bukhaari and Muslim Shareef / Mishkaat,
page 68]

The glad-tidings of full illumination (on the Day of Qiyaamah) for those who attend the Musjid during the dark hours

“It has been reported by Hadhrat Buraidah (radhiallahu anhu) that Rasulullah (sallallahu alayhi wasallam) said, ‘Glad tidings of complete illumination on the Day of Qiyaamah to those who proceed to the Musjid in the dark.’ [Abu Dawood / Tirmidhi / Mishkaat, page 69] Those who proceed towards the Musjid in the dark hours, and are not deterred by it (or by any other apparent hindrance), will be granted a total and full noor (illumination) on the Day of Qiyaamah, in lieu of their bearing this difficulty. This noor will be such that it will outshine the radiance of the sun. There is another narration which states that such persons will be seated on pulpits of noor on the Day of Qiyaamah. In one Hadith Nabi (sallallahu alaihi wasallam) states that whosoever enjoys an attachment for the Musjid, Allaah Ta`ala establishes an attachment and affection for him.

Nabi (sallallahu alaihi wasallam) had practiced such rigidity in attending the Musjid for Salaat, that even during his terminal illness, he would attend the Musjid for Salaat, taking assistance from the Sahaabah (radhiallahuanhum). The Ahaadith demonstrate the importance that the Sahaabah (radhiallahu anhum) attached to attending the Musjid for Salaat; theywould come to the Musjid from far off. Neither would the darkness of the night nor the heat of the midday deter them from attending the Musjid. Inessence, these personalities held firm and full belief and trust in the words of Nabi (sallallahu alaihi wasallam). They would grant preference to theblessed words of Nabi (sallallahu alaihi wasallam) over their own opinions. Hadhrat Abu Darda (radhiallahu anhu) once wrote a letter of advice to Hadhrat Salmaan Farsi (radhiallahu anhu) wherein he stated that the Musjid is the house of the pious Allaah-fearing people and that Allaah Ta`ala has given assurance that whosoever regularly attends the Musjid, will be granted peace and contentment, they will be made to traverse the Pul Siraat with ease and they will be blessed with the Pleasure of Allaah Ta`ala.

The connection of our Nabi (sallallahu alaihi wasallam) to the Musjid

“It has been reported by Hadhrat Ka`ab bin Maalik (radhiallahuanhu) that Nabi (sallallahu alaihi wasallam) would not return home from a journey except during the day at Chaasht time (mid-morning). When he returned, he would first proceed to the Musjid and perform two Rakaats of Salaat therein and then he would sit down.’” [Bukhari and Muslim Shareef
/ Mishkaat, page 68]

This Hadith of Hadhrat Ka`ab bin Maalik (radhiallahu anhu) demonstrates the intricate connection Nabi (sallallahu alaihi wasallam) had with the Musjid, that immediately upon returning from a journey he would proceed immediately to the Musjid. After completing his Salaat he would give a sermon or engage in some work or the other. After the demise of Nabi (sallallahu alaihi wasallam) this became the normal and regular practice of the Sahaabah (radhiallahu anhu) that when that returned from a journey they would first proceed to the Musjid and the only after performing Salaat go to their homes. Upto this day, this remains a Sunnat practice. Whenever any important or significant event presented itself to Nabi (sallallahu alaihi wasallam), he would proceed to the Musjid. Hadhrat Abu Darda (radhiallahu anhu) reports that whenever a severe storm arose, Nabi (sallallahu alaihi wasallam) would immediately proceed to the Musjid and he would leave until the storm dissipated.