The temptation, when we lift these passages out of their larger story, is to embrace self-sufficiency. If we just try harder, we can do what God says in the law; if we try even harder, we can do what Jesus says in the sermon on the mount. I can’t speak for anyone else, but my track record of just trying harder is not so great.
It’s an idolatrous world out there. The good news of the Gospel is that when we go out into that world as a blessed people, we bring God’s blessings with us.
The good news here is that it is Jesus who takes away the sin of the world, not you and me. It is Jesus who scoops up all the ways that we have fallen short, all the ways that this broken and violent world falls short of God’s intention, all the horrors of war, criminal behavior, illness, and despair, and takes them away. The good news is that forgiveness is not a burden placed upon us, but a gift.