Christianity is the largest, and most influential, religion in the world, with 31% of the world's populations being followers.

Christianity originated from the religion organized by King Josiah of Judah, and was established by Jesus of Nazareth in the 1st century AD.
Christian belief places emphasis on forgiveness and redemption.

The Christian Holy text is known as the Bible, although there are four different versions (not to be confused with translations), these versions are the Catholic Bible, which has 73 books, the Orthodox Bible, which has 79 books, the Protestant Bible, which has 66 books, and the Ethiopian Bible, which has 80 books.
Now, let me clear something up, people will say that the Protestant reformer Martin Luther removed a set of books from the Bible because they were too Catholic, this is false, the official canon was not decided until Luther canonized the 66 books we have now, the Catholic church canonized their 73 shortly after; the Orthodox, however, had always used the 79 they currently use, and the Ethiopians much the same, although they have the Book of Enoch as canon unlike all other Christian traditions.
Other Christian writings are, the Didache, which is an early Christian writing that summarizes the beliefs of Christians from the Antioch area and is known as the oldest non-Biblical Christian text, and the writings of the Church Fathers, which are multiple sets of writings by the early elders and Saints of the Church.

The practices of Christians include the Sacraments, which are Baptism, the practice of immersion in water to signify the washing away of sins, Holy Communion/The Eucharist/The Lords Supper, which is the practice of eating wafers and drinking wine (and sometimes grape juice) in fulfillment of the command of Jesus to "eat His body and drink His blood", and, in addition to these Catholics have Confirmation, Reconciliation, Anointing of the sick, Marriage (yes, Protestants get married, it isn't a sacrament for them though), and Ordination, Orthodox have others, in addition to Baptism and Communion they have Chrismation, Confession, Marriage, Anointing of the sick, and Holy Orders. Now, there are different views on all of these, with there being exceptions to who practices each, but this is the summary of the Sacraments.
Other practices do exist and can be summarized in the phrase "Thy will be done on Earth as is in Heaven" or making Earth better in preparation for Heaven.

To conclude, Christians believe that Jesus, whom we call Christ Messiah, is God incarnate who was birthed to the Virgin Mary and came down to Earth to die as payment for our sins, all past and future sins, and that He rose on the third day after His death and ascended to Heaven forty days after. And that we believe in one God, who is three persons, The Father, The Son, and the Holy Ghost, who are all God equally, yet have different wills, which we call the Most Holy Trinity. And Christ, He has two natures, a human and a divine, which have two distinct, but not separate, wills.