The Our Father is the oldest of Christian prayers, going back to Jesus Christ himself, who, in Matthew 6:9-13, taught his disciples to pray in these words. Because the prayer came from Christ, it is used in every Mass, and we should pray it daily.
The Our Father
"Our Father who art in heaven, hallowed be Thy name; Thy Kingdom come; Thy will be done on earth as it is in heaven. Give us this day our daily bread; and forgive us our trespasses as we forgive those who trespass against us; and lead us not into temptation, but deliver us from evil. Amen."