Prayer is the first thing for which a person will be brought to account on the Day of Resurrection:
It was narrated that Abu Hurayrah (may Allaah be pleased with him) said: I heard the Messenger of Allaah (Sallallahu Alaihi wa Sallam) say
“The first deed for which a person will be brought to account on the Day of Resurrection will be his prayer. If it is good
then he will have prospered and succeeded, but if it is bad then he will be doomed and have lost.
If anything is lacking from his obligatory prayers
, the Lord will say, ‘Look and see whether My slave did any voluntary prayers, and make up the shortfall in his obligatory prayers from that.’
Then all his deeds will be dealt with likewise.”
Narrated by al-Nasaa’i, 465; al-Tirmidhi, 413. Classed as saheeh by al-Albaani in Saheeh al-Jaami’