Jesus did not proclaim the sermon on the mount so that we would, Tolstoy-like, furrow our brows in despair over our failure to achieve perfection. He gave it to impart to us God's ideal toward which we should never stop striving, but also to show that none of us will eve reach that Ideal. the sermon on the mount forces us to recognize the great distance between God and us, and any attempt to reduce that distance by somehow moderating its demand misses the point altogether.

Yancey, Jesus I Never Knew, loc 2109