If God already knows what we need, then why pray at all? We do not pray to instruct God, but to become intimate with Him to be reminded of our sins and our neediness.
Christians have always been instructed to recite the Lord’s Prayer, at least three times a day. The instruction by Jesus is to begin the prayer by saying “Our Father” was unique. Abba, or Father in Aramaic, was a term of respect for old men, but the Jews never addressed God that way in prayer. By encouraging us to address God as Father, Jesus affirms the possibility of an intimate relationship with God who loves us and cares for us. We can approach Him and rely on Him with total trust and confidence.