"If today's young people are looking for the right things (meaning, love, reality), they are looking for them in the wrong places. The first place they should be able to turn to is the one they normally ignore, the church. For too often what they see in the church is not a new society which embodies their ideals but another version of the old society which they have renounced.
No comment could be more hurtful to the Christian than the words "But you are no different from anybody else." For the essential theme of the whole Bible from beginning to end is that God's historical purpose is to call out a people for himself. This people is a "holy" people, set apart from the world to belong to him and to obey him; its vocation is to be true to its identity, that is, to be "holy" or "different" in all its outlook and behavior.
All this is essential background to the Sermon on the Mount. It describes what human life and human community look like when they come under the gracious rule of God. And what do they look like? Different. (John Stott's The Beatitudes: Developing Spiritual Character p.5-6).
That which Stott calls 'the gracious reign of God' is precisely what Matthew refers to when he uses the phrase: "kingdom of heaven/God". The beatitudes pronounce the blessings of the kingdom. This dawning kingdom ushers in a new reality, the firstfruits of the new creation which brings with it the gospel power to create a new community.