To most people in our society, Christianity is religion and moralism. The only alternative to it (besides some other world religion) is pluralistic secularism. But from the beginning it was not so. Christianity was recognized as a tertium quid, something else entirely.
The crucial point here is that, in general, religiously observant people were offended by Jesus, but those estranged from religious and moral observance were intrigued and attracted to him. We see this throughout the New Testament accounts of Jesus’s life. In every case where Jesus meets a religious person and a sexual outcast (as in Luke 7) or a religious person and a racial outcast (as in John 3-4) or a religious person and a political outcast (as in Luke 19), the outcast is the one who connects with Jesus and the elder-brother type does not. Jesus says to the respectable religious leaders “the tax collectors and the prostitutes enter the kingdom before you” (Matthew 21:31).
Jesus’s teaching consistently attracted the irreligious while offending the Bible-believing, religious people of his day. However, in the main, our churches today do not have this effect. The kind of outsiders Jesus attracted are not attracted to contemporary churches, even our most avant-garde ones. We tend to draw conservative, buttoned-down, moralistic people. The licentious and liberated or the broken and marginal avoid church. That can only mean one thing. If the preaching of our ministers and the practice of our parishioners do not have the same effect on people that Jesus had, then we must not be declaring the same message that Jesus did. If our churches aren’t appealing to younger brothers, they must be more full of elder brothers than we’d like to think.
Timothy Keller, The Prodigal God (pp. 17-19).
Following Jesus seemed easy enough at first, but that was because they had not followed him very far. It soon became apparent that being a disciple of Christ involved far more than a joyful acceptance of the Messianic promise: it meant the surrender of one’s whole life to the Master in absolute submission to his sovereignty….This was strong teaching. Not many people could take it. They liked to be numbered among his followers when he filled their stomachs with bread and fish, but when Jesus started talking about the true spiritual quality of the Kingdom and the sacrifice necessary in achieving it (John 6:25-29), many of his disciples “went back, and walked no more with him” (John 6:66). As they put it, “This is a hard saying: who can hear it?” (John 6:60). The surprising thing is that Jesus did not go running after them to try to get them to stay on his membership roll. He was training leaders for the Kingdom, and if they were going to be fit vessels of service, they were going to have to pay the price.
Robert Coleman, The Master Plan of Evangelism (pgs. 50-51).
So, first of all, Christians must be like their neighbors in the food they eat and clothes they wear, their dialect, general appearance, work life, recreational and cultural activities, and civic engagement. They participate fully in life with their neighbors. Christians should also be like their neighbors with regard to excellence. That is, Christians should be very good at what others want to be good at. They should be skillful, diligent, resourceful, and disciplined.
Second, Christians must be also unlike their neighbors. In key ways, the early Christians were startlingly different from their neighbors; it should be no different for us today. Christians should be marked by integrity. Believers must be known for being scrupulously honest, transparent, and fair. Followers of Christ should also be marked by generosity. If employers, they should take less personal profit so customers and employees have more pay. As citizens, they should be philanthropic and generous with their time and with the money they donate for the needy. They should consider living below their potential lifestyle level. Believers should also be known for their hospitality, welcoming others into their homes, especially neighbors and people with needs. They should be marked by sympathy and avoid being known as self-serving or even ruthless in business or personal dealings. They should be marked by an unusual willingness to forgive and seek reconciliation, not by a vengeful or spiteful spirit.
Timothy J. Keller, Center Church: Doing Balanced, Gospel-Centered Ministry in Your City (pg. 282-283).