The gospel is the power by which the world is overcome. The world will know we are Christians by our love, but all love flows from the grace we have been given by God.
Christian love is supernatural in origin. It flows from our union with Christ in his death and the Holy Spirit working in our hearts.
You see we cannot try to imitate Jesus' life with out accepting his divinity and saving work. The reason is that the power to live out Jesus' teachings in the world is supernatural in origin. That is why he told his apostles to await Pentecost.
Often preachers wish to have their congregation live more faithfully to the teaching of scripture by teaching a steady diet of law. Law is certainly of use, but often the most lawless living is by those in the church that wish to live out the law but do not understand the gospel.
You see this is the situation which the Pharisees were in. They had great zeal to live out the law but did not really understand the meaning of true religion. This is why they accused Jesus of lawlessness at some of his most ethically beautiful moments.
Legalism is always a prevalent faction in the church wherever the church is. It tries to keep the letter of the law while greatly misunderstanding the spirit of the law.
We must first trust in the saving work of Jesus and only then begin to imitate his life. Of course Jesus commands that we follow him. We must first accept that he is God and his work, death, and resurrection and then begin to try to live like him through the power given through faith.