Jesus didn't want us to use many words when we pray. That makes me think, those things he did tell us to say must really matter. He wanted us to come to God and call him Father. He wanted us to say 'our' Father, while praying alone in our room - so always treasuring and identifying with our siblings, as God does, is central to our most intimate individual worship. He wanted us to think of God's reign in heaven, where everything is ordered according to his will. He wanted us to long for the same situation on earth - our Father's reputation revered and his will enacted. What is God's reputation and his will? That the needs of us all are met, each day for that day. That we are all forgiven for our sins as we forgive those who sin against us. That we all be guided on the right path away from temptation, and rescued from calamity. Jesus wanted us to desire this dominion of God to be the reality here on earth and to ask for it. Our Father already knows we need these things before we ask for them, and he delights to give us good things, so we should ask for these things and expect to receive them, as we will receive them. And Jesus said it really is our Father's will for us that we forgive our siblings from our heart.