In spite of two thousand years of growth and change, there are still some hallmarks that distinguish Christianity from all other, similar or not-so-similar, religious sects. While the range of beliefs among Christians can be quite wide, the following represent what is commonly shared.
The Goodness of Creation, Made by God
Most Christians believe that the physical universe, including humanity itself, is fundamentally good, even though human beings cause it harm through their negligence and self-interest. Other Christians hold that while humanity may be flawed, God's love and grace provides a way to perfection and goodness through the teachings and saving presence of Jesus Christ.
The Bible as the Word of God
Christians believe that the Bible is "the Word of God," and as such, "contains all things necessary to salvation." While there have been countless books about Christianity written since the Bible, and while many of the other doctrines essential to Christianity have been worked out in them, the Bible is sufficient to knowing God through Jesus Christ and to benefiting from the saving act of the Resurrection. Christians may disagree regularly, however, on how to interpret or apply what the Bible says.
The Trinity: One God in Three Persons
Christians believe in one God, whom we understand to exist in three "persons," traditionally referred to as "Father, Son, and Holy Spirit." The three "persons" of the Trinity are God, who created all things, Jesus Christ, his fully human(and at the same time, fully divine) son, and the Holy Spirit of God who gives life to all things and moves through all living things. Contemporary language now acknowledges other images of the Trinity, such as "Creator, Redeemer, and Sanctifier," but the Trinity remains One God in three persons.
The Incarnation: God Became Human
Christians believe that Jesus Christ was, at the same time, completely human and completely God, all in one person. This idea was articulated and adopted to address variants to Christian theology (known as "heresies"), which arise from time to time throughout history. One heresy has claimed that Jesus didn't really die on the cross because he wasn't really human. An opposing heresy claims that he was really just an important guy with some great ideas, and that he wasn't really God.
The Crucifixion and Resurrection
Christians believe that Jesus of Nazareth died completely on the cross, that he was buried in a tomb, and that on the third day, he was raised physically again to life to return to his disciples.
Baptism is the sacrament whereby people become Christians, and thereby members of the Church. At Baptism, the new Christian (or in the case of a child, the parents or guardians) professes belief in Jesus, renounces evil before the Church, and then is immersed in (or sprinkled with) water three times(in the name of the Father, and of the Son, and of the Holy Spirit. Baptism represents our participation in the death and resurrection of Jesus, and assures us of our salvation through belief in him.
All baptized Christians participate in the Eucharist (from the Greek, meaning "Thanksgiving") or as it is also called "Holy Communion," "the Lord's Supper," or "The Mass." The Eucharist was instituted, according to the Bible, by Jesus himself on the night of his arrest, before he was crucified. During the Eucharist, bread and wine are blessed as symbols of Christ's body and blood. The bread is broken and shared, and then the cup of wine is passed among the worshipers as a sign of Jesus' sacrifice on the cross and resurrection. The Eucharist is a continual remembrance of Jesus' life, death, and resurrection until he comes again.
Working for the Reconciliation of the World to God through Jesus Christ
All Christians share in God's work of reconciling the world to God's self. In other words, Christians believe that in Jesus Christ, all divisions among people, all injury, all wrong, and all sinfulness can be healed, and it is every Christian's responsibility and ministry to work for that healing. Christians believe that there will come a day when the world will be completely at peace, sharing in God's love, and living as one Body.