Salamu alaikum, I need to know in case a person has doubts about having performed a pillar during prayer. If he neglects that doubt and move on, is the prayer still valid? Will Allah punish me for something I forgot?Sometimes I doubt whether I have missed one sujood or rukuh and some of these times I decide to neglect these doubts and move on. Will my prayer be valid?I know there is a ruling that says if I keep having the same doubt then I should ignore it. What if instead one doesn't ignore it? What if the doubt engrosses in one's mind and he acts upon it? Will in this case his prayer be valid?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad, sallallaahu`alayhi wa sallam, is His Slave and Messenger.

If the doubt that occurred to you was in one of the pillars of the Prayer, such as the bowing, the prostration, or the like, and if it happened after you had concluded the Prayer, then the Sharee'ah ruling in this is that you ignore it and it has no effect whatsoever, and your Prayer is still valid. However, if it is during the Prayer, then you have to perform what you doubted, and then prostrate the Two Prostrations of Forgetfulness, based on the Hadeeth of the Prophet, sallallaahu`alayhi wa sallam, “When any one of you is in doubt about his Prayer and he does not know how much he has prayed, three or four Rak'ahs, he should cast aside doubt and base his Prayer on what he is sure of, then perform the two prostrations before concluding the Prayer with Salam. If he has prayed five Rak'ahs, they will make his Prayer an even number for him, and if he has prayed exactly four, they will be a humiliation for the devil.” [Muslim]. Whoever performs what he has doubted, in this case, then his Prayer is valid, but whoever did not perform what he doubted until he concluded his Prayer with Salam and the duration after the Prayer was long, then his Prayer is invalidated, because having doubt in performing the pillars during the Prayer is just like not performing them at all. Ibn Qudaamah said in Al-Mughni, “If he doubts missing a pillar of the Prayer while he is still praying - did he violate it or not? The Sharee'ah ruling, in this case, is that it is considered as not performing it, whether one is praying as an Imam or alone, because the original state is that it is non-existent.” [End of quote]

As regarding the one who keeps having doubts- as you mentioned - then the Sharee'ah ruling is that he should ignore his doubts, and does not perform the Two Prostrations of Forgetfulness for the doubt. The guideline for the doubts to be considered as frequent doubts is the occurrence of the doubt every day, even if only once a day. In such case, he always performs the Two Prostrations of Forgetfulness after the Prayer for whatever he doubts. However, if he gives in to his doubts and acts upon the least, then his Prayer is still valid because he performed it in the manner that is originally performed.

Allah Knows best.