In attempting to define something it can be helpful to identify what it is not. Christianity is not simply an emotional exhortation to virtue. It is not simply a truth or a doctrine to be recognized intellectually. Christianity is not a collection of rituals and of demanding rules and regulations. Rules and regulations have their place, their importance. But rules and regulations present a double danger. Scrupulous adherence to rules may lead to presumption, to thinking such observation can save one even when there is a lack of justice and charity. At the opposite extreme, callous neglect of rules is a sign of a deadened conscience. In any case rules and regulations are not of the essence of Christianity.
Christianity is divine in its origin but comprised of human beings. This latter fact explains how and why it has often been marred in its history.
Christianity demands total commitment. Luke (14: 26-27) records some very strong words of Jesus. “Anyone who comes to me without hating his father, mother, children. brothers, sisters, yes, even his own life, cannot be my disciple.” However one interprets those words they clearly imply total commitment is required of followers of Christ.
And more. The Christian can expect revilement and persecution for no other reason than their Christianity. “If you find that the world hates you, know that it has hated me before you. If you belonged to the world it would love you as its own; the reason it hates you is that you do not belong to the world. Not only will they expel you from synagogues; a time will come when anyone who puts you to death will claim to be serving God.” (John 15: 18-20; 16: 2-3)
Christianity is centered in the person of Jesus Christ. As C.S. Lewis pointed out “Christianity exists for nothing else but to draw people to Christ. If it is not doing that, all the clergy, missions, sermons, even the Bible itself are a waste of time.”
To the question: “What is the essence of Christianity?” many, if not most people would reply: “Love of God and love of neighbor.” Those so-called commandments of charity are of supreme importance. They are not, however, the specific essence of Christianity. Every major religion insists on reverence for the Supreme Being, however conceived, and contains some form of the golden rule. What is specific and essential to Christianity is the belief that Jesus Christ is the Son of God and savior of the world.