Ten Commandments, Salvation, Trinity And Jesus Christ.
The Ten Commandments are a set of biblical principles relating to ethics and worship which play a fundamental role in Judaism and most forms of Christianity. They include instructions to worship only God and to keep the Sabbath, and prohibitions against idolatry, blasphemy, murder, theft, and adultery. Different groups follow slightly different traditions for interpreting and numbering them. According to the synoptic gospels, Christ generalised the law into two underlying principles; The first is “Hear, O Israel: The Lord our God, the Lord is one; and you shall love the Lord your God with all your heart, and with all your soul, and with all your mind, and with all your strength.” While the second is “You shall love your neighbour as yourself.”[Matthew 22:34-40][Mark 12:28-33]
These are quotes from Deuteronomy 6:4 and Leviticus 19:18. Barnes’ Notes on the New Testament comments on these verses saying: “These comprehend the substance of what Moses in the law, and what the prophets have spoken. What they have said has been to endeavour to win men to the love of God and each other. Love to God and man comprehends the whole [of] religion; and to produce this has been the design of Moses, the prophets, the Saviour, and the apostles.”
The central tenet of Christianity is the belief in Jesus as the Son of God and the Messiah (Christ). Christians believe that Jesus, as the Messiah, was anointed by God as savior of humanity, and hold that Jesus’ coming was the fulfillment of messianic prophecies of the Old Testament. The Christian concept of the Messiah differs significantly from the contemporary Jewish concept. The core Christian belief is that through belief in and acceptance of the death and resurrection of Jesus, sinful humans can be reconciled to God and thereby are offered salvation and the promise of eternal life.
While there have been many theological disputes over the nature of Jesus over the earliest centuries of Christian history, Christians generally believe that Jesus is God incarnate and “true God and true man” (or both fully divine and fully human). Jesus, having become fully human, suffered the pains and temptations of a mortal man, but did not sin. As fully God, he rose to life again. According to the Bible, “God raised him from the dead”, he ascended to heaven, is “seated at the right hand of the Father”and will ultimately return[Acts 1:9–11] to fulfill the rest of Messianic prophecy such as the Resurrection of the dead, the Last Judgment and final establishment of the Kingdom of God.
According to the canonical gospels of Matthew and Luke, Jesus was conceived by the Holy Spirit and born from the Virgin Mary. Little of Jesus’ childhood is recorded in the canonical Gospels, however infancy Gospels were popular in antiquity. In comparison, his adulthood, especially the week before his death, is well documented in the Gospels contained within the New Testament. The Biblical accounts of Jesus’ ministry include: his baptism, miracles, preaching, teaching, and deeds.
DEATH AND RESURRECTION OF JESUS
Christians consider the resurrection of Jesus to be the cornerstone of their faith (see 1 Corinthians 15) and the most important event in human history. Among Christian beliefs, the death and resurrection of Jesus are two core events on which much of Christian doctrine and theology is based. According to the New Testament Jesus was crucified, died a physical death, was buried within a tomb, and rose from the dead three days later.[Jn. 19:30–31] [Mk. 16:1] [16:6]
The New Testament mentions several resurrection appearances of Jesus on different occasions to his twelve apostles anddisciples, including “more than five hundred brethren at once”,[1Cor 15:6] before Jesus’ Ascension to heaven. Jesus’ death and resurrection are commemorated by Christians in all worship services, with special emphasis during Holy Week which includes Good Friday and Easter Sunday.
The death and resurrection of Jesus are usually considered the most important events in Christian theology, partly because they demonstrate that Jesus has power over life and death and therefore has the authority and power to give people eternal life.
Christian churches accept and teach the New Testament account of the resurrection of Jesus with very few exceptions. Some modern scholars use the belief of Jesus’ followers in the resurrection as a point of departure for establishing the continuity of thehistorical Jesus and the proclamation of the early church. Some liberal Christians do not accept a literal bodily resurrection, seeing the story as richly symbolic and spiritually nourishing myth. Arguments over death and resurrection claims occur at many religious debates and interfaith dialogues. Paul the Apostle, an early Christian convert and missionary, wrote, “If Christ was not raised, then all our preaching is useless, and your trust in God is useless.”[1Cor 15:14] 
Paul of Tarsus, like Jews and Roman pagans of his time, believed that sacrifice can bring about new kinship ties, purity, and eternal life. For Paul the necessary sacrifice was the death of Jesus: Gentiles who are “Christ’s” are, like Israel, descendants of Abraham and “heirs according to the promise”.[Gal. 3:29]  The God who raised Jesus from the dead would also give new life to the “mortal bodies” of Gentile Christians, who had become with Israel the “children of God” and were therefore no longer “in the flesh”.[Rom. 8:9,11,16] 
Modern Christian churches tend to be much more concerned with how humanity can be saved from a universal condition of sin and death than the question of how both Jews and Gentiles can be in God’s family. According to both Catholic and Protestant doctrine, salvation comes by Jesus’ substitutionary death and resurrection. The Catholic Church teaches that salvation does not occur without faithfulness on the part of Christians; converts must live in accordance with principles of love and ordinarily must be baptized. Martin Luther taught that baptism was necessary for salvation, but modern Lutherans and other Protestants tend to teach that salvation is a gift that comes to an individual by God’s grace, sometimes defined as “unmerited favor”, even apart from baptism.
Christians differ in their views on the extent to which individuals’ salvation is pre-ordained by God. Reformed theology places distinctive emphasis on grace by teaching that individuals are completely incapable of self-redemption, but that sanctifying grace is irresistible. In contrast Catholics, Orthodox Christians and Arminian Protestants believe that the exercise of free will is necessary to have faith in Jesus.
Trinity refers to the teaching that the one God comprises three distinct, eternally co-existing persons; the Father, the Son(incarnate in Jesus Christ), and the Holy Spirit. Together, these three persons are sometimes called the Godhead,although there is no single term in use in Scripture to denote the unified Godhead. In the words of the Athanasian Creed, an early statement of Christian belief, “the Father is God, the Son is God, and the Holy Spirit is God, and yet there are not three Gods but one God”. They are distinct from another: the Father has no source, the Son is begotten of the Father, and the Spirit proceeds from the Father. Though distinct, the three persons cannot be divided from one another in being or in operation.
The Trinity is an essential doctrine of mainstream Christianity. “Father, Son and Holy Spirit” represents both the immanence andtranscendence of God. God is believed to be infinite and God’s presence may be perceived through the actions of Jesus Christ and the Holy Spirit.
According to this doctrine, God is not divided in the sense that each person has a third of the whole; rather, each person is considered to be fully God (see Perichoresis). The distinction lies in their relations, the Father being unbegotten; the Son being begotten of the Father; and the Holy Spirit proceeding from the Father and (in Western Christian theology) from the Son. Regardless of this apparent difference, the three ‘persons’ are each eternal and omnipotent.
The word trias, from which trinity is derived, is first seen in the works of Theophilus of Antioch. He wrote of “the Trinity of God (the Father), His Word (the Son) and His Wisdom (Holy Spirit)”. The term may have been in use before this time. Afterwards it appears in Tertullian. In the following century the word was in general use. It is found in many passages of Origen.