Christianity is not a “system” of morality for the world to subscribe to. The principles of the Bible, and the teaching of Jesus are not intended to provide a “system” of religious/moral discipline apart from a relationship with God!
Some see the moral principles of Scripture as a divinely sent constraint within which man must live, in order to please God. But Jesus made clear that true spiritual life comes from a newly created life, a “born again” life that is created to interact directly with God, by His Spirit, through the gracious provision of life made available in Christ.
Jesus criticized the Pharisees, the religious leaders of his day, because they taught (enforced?) a system of moral adherence. Spirituality was reduced to an outward compliance, mostly to human traditions and ritual, rather than an inward life of the spirit. Jesus turned their approach upside down when he said he was the “vine”, and his followers were the “branches” who needed to “abide” in him in order to receive spiritual life. (John 15)
Christianity was begun as a movement of people living out the life of Christ in them, in community together, each person expressing the giftedness of the Spirit by the guidance of the apostle’s teaching, prayer and worship. But sadly, Christianity has become institutionalized as it ushers people into an organizational chart with church walls built around it, with the goal of training people to do the “right” things; e.g., go to church, tithe, “get involved”, etc. It becomes hard to discern the difference between those who truly live out the life of Christ, by the power of the Spirit, from those who simply change their habits.
An example of how this “plays out” is seen in the current tendency Christians have to address the political issues of the day, thinking their role is to inject “morality” into the culture. In fact, the Christian “calling” is to present the gospel, because only in it, is found the true liberation of the soul, and willingness to live by the high moral calling of God upon humanity. The church is losing it’s way because it promotes “morality” instead of the soul-transforming power of God. And so Christians feel the need to “speak out” when in fact they’re moralizing, as though that is the message of God to the world, when it isn’t at all.
What if the world did as the Christian church proclaims; it rejected homosexuality, confined marriage to a man and woman and rejected abortion? What if the world obeyed the precepts of Jesus? What we might have, is the world somewhat better morally “controlled”, but still not living the life of Christ in the power of the Spirit. And as a result, would not see true Christianity lived!