Importance of Prayer (salat,namaz)
Wajib (must do) - Praying allows a person to Heavenly reward, but if a person doesn’t pray he will get revenge in the after he/she dies!
The Holy Prophet has said: “If Allah accepts one’s Prayers, other good deeds of his will also be acceptable to God. But if one’s Prayer is rejected by Allah, his other good actions will be surely rejected.”
The Holy Prophet has also said: “Everything has something to beautify. And the thing that beautify Islam is the obligatory Prayer, 5 times a day. Everything has support, and the support for a Momin (Faithful) is this very Prayer. Everything needs some sort of light, and for the heart of a Momin (faithful) this Prayer serves as a light. Everything carries some price, and the price of Paradise is Prayer. Prayer is a way of repentance for a repentant and a source of happiness. It is through this very Prayer that the devotee can hope for Generosity of Allah, the acceptance of his Prayers and the end of his sins.”
Imam Jafar-e-Sadiq has said, “One who is careless of Prayer and has no regard for it, does not belong to us, and will surely be excluded of the benefit of our intercession. (on the day o Judgement.”
“Praying,” says the Prophet o Islam, “is the rescue of the true believer, the piller of faith, and the light of heaven on earth.”
“The best dedication,” says Hazrat Ali, “is to stay away from what is not allowed; and the most pleasant of earthly acts to God, is to pray to Him, for prayer turneth away a decree even though ordained; it is the key of mercy, the means whereby needs are satisfied and every hardship warded off.”
“Whoever prays,” says Imam Muhammed Baqir, “shall never want.” And he once said to Mir (one of his followers), “O Mir, pray and do not say whatever is ordained shall come to pass. Verily there is a rank of nearness to God, which cannot be obstained save by prayers and entreaty.”
To the question, what was the best devotional act? He replied that there was nothing more agreeable to God than praying and entreaty, or God loved those who pray to Him, and that there was nothing more hateful to Him, than those who are proud and abstain from devotion and prayer.
Hazrat Ali has said: “Offer your prayers regularly, be careful when you are offering them, pray as often as you possible can and through prayers seek the nearness of His Realm. Prayers are made wajib for faithful Muslims. Have you not read in the Holy Quran the reply of those who would be thrown in Hell? When they will be asked: What has brought you to Hell, they will say, We were not amongst those who prayed.”
Recite what is sent of the Book by inspiration to thee, and establish regular prayer. For prayer restrains from shameful and unjust deeds; and remembrance of God is the greatest (thing in life) without a doubt. And God knows the (deeds) that ye do. 29:45 Holy Quran
Call on Me: I will answer your (prayer). But those who are too arrogant to serve Me, will surely find themselves in Hell, in humiliation 40:60, Holy Quran
Reference: Know your Islam by Yousuf N. Lallajee pg.14, and 36