Christ’s exalted ethical teaching in [the Sermon on the Mount] is not wholly unique. One can find equivalents or near-equivalents for nearly everything here in some of the rabbis, and in Socrates, Solomon, Buddha, Confucius, and Lao Tzu. These profound men intuited from afar something of the high goal we are called to; but they did not know the way. Jesus not only knew the way but was the Way. He did not say, like Buddha, “Look not to me, look to my teaching (dharma).” He said the exact opposite: “I am the way… no one comes to the Father except through me” (John 14:6). Jesus is a teacher, and the best one, although not the only one. However, he is the only Way, the only Savior, the only Jesus.
Yet although Jesus’ ethical teachings in this Sermon are not the essence of Christianity, they are essentially connected with it. The essence is Christ, Christ-for-us, our New Birth in Christ. But new birth is followed by new life, and this sermon describes that new life. Children’s lives resemble their parents’; and when we become children of God by faith and baptism, we begin to resemble him and our lives begin to resemble his life.
– Peter Kreeft, “The Beatitudes Confront the Seven Deadly Sins,” Back to Virtue, p. 83-84.