The Model Prayer
In what is popularly referred to as the "Lord's Prayer" Jesus took His teaching from Matthew 6:5-8 (calling for humility and truth in prayer) and applied it with the Model Prayer (6:9-15).
This was not originally intended as a prayer to repeat over and over again, but was to be a prayer example for disciples of Christ to follow.
"Pray, then, in this way:" was Jesus' preface to this prayer. In other words, He wanted us to pray in a similar fashion. We also saw that Jesus could never have prayed this prayer on behalf of Himself, since forgiveness is asked for, and the Lord is the sinless one. So then, it's an excellent model or example of prayer for us.
Jesus did not leave His disciples without cause to pray or without a way to pray. He wanted to be sure that His followers, then and now, would know how to come humbly before the Father, through Christ, indwelled by the Holy Spirit, with their every prayer and petition.