What is prayer?

What is prayer? God is omniscient and omnipotent. He knows all my things, my thoughts and needs, why do I still pray, and ask God to help me? Sometimes I prayed hard, but God did not accomplish it. I do not know why I still pray?

Prayer is communion with God. Do you know why Jesus prayed. He is God, he has power. He has no sin to repent. But He still pray. Because He loves Him.
He knows all my things, my needs. but in fact,we don’t know what we need, I think God has already answered your prayer but sometimes, God gives us what we need which we don’t know.

Prayer is the communication with God. Although God is the God of omniscience and omnipotence, the relationship between us and God is the relationship of love and mutual need. God wants us to respond in love. And ask God for help.
If you pray very hard, but you haven’t done it yet, then you may need to wait for God, or you need to continue to pray, and the accumulation of quantity will be accomplished. Or there are other God’s wills to seek.