Well, the Lord's Prayer doesn't say that. Jesus says that we can pray for our daily bread, for what we need. We can pray for forgiveness, which is the same as praying to be healed. And we can pray not to be tested, beyond our ability to bear. Temptation is real.
Adults know what it's like, to be tempted.
We're invited, every day, to give in to pressures and to seductive thoughts and activities. The world is constantly urging us to conform to its ways, rather than to be transformed by the burning, living, redeeming love of God. It's OK to ask, as an adult, for help in dealing with temptation. Every one of us has a different collection of self-destructive fantasies and temptations, which eat away at our faith and our love and our understanding. But no matter how sophisticated our understanding is of things like politics, and economics, and disease, and the causes of things like war and hunger and suffering, our prayer can always be simple.