Muhammad (PBUH) said: ‘The first of one’s actions for which a slave of Allah will be held accountable on the Day of Judgment will be one’s prayers. If they are correct and accounted for, then he (or she) will have succeeded (gained paradise); and if they are lacking, then he (or she) will have failed (lost paradise).

If there is something defective in his (or her) obligatory prayers, the Lord will say: ‘See if my slave has any supererogatory prayers with which that which was defective in his (or her) obligatory prayers may be completed. Then the rest of his (or her) deeds will be judged in like manner.’ (At-Tirmidhi and others)