In I got It!
The Gentile's Division
Tehillim-the Book of Psalms is the only holy book divided into chapters by our Sages and not gentiles.
During the middle Ages, in the year 4965, Archbishop Stephen Langton of Canterbury, Britain, divided the Bible into chapters for the purpose of turning it into an accessible source of information for the Christians. The information derived from the Bible would then serve the church in the debates that were conducted between priests and Jewish Rabbis at the request of the church.
The purpose of these debates was to 'prove' that the 'man from Nazareth' is mentioned in the Bible and that the Bible indicates that Christianity is the true religion.
In order to reduce the hard work of the priests in searching for suitable verses that prove their point, Archbishop Langton divided the Bible into chapters and verses.
This Christian division made its way into the Jewish publishing houses as the years passed and eventually became acceptable within the Jewish community. The division, which was supposedly based on the logic of the Archbishop and his comprehension of the Bible's text – actually, in many cases, does not make sense at all and do not match the Torah Portions. Take for example the Torah Portion of Balak, which begins with verse 2, as does the Torah Portion of Matot, while what should be the first verse appears as the last verse of the previous portions, etc.
The fact that the person behind the division was Christian and was motivated by personal gain is clearly evident in the division. A very obvious example is the division of Genesis: According to Archbishop Langton's division, the first chapter, which describes the creation of the world during the six days of creation, does not include the climax of creation - the resting day of Sabbath, which is mentioned only in the next chapter. Excluding the Sabbath from the week of creation serves the Christians' purpose of indicting that the first day of creation, Sunday, which is described in the very beginning of Genesis, is the holy day, as opposed to Sabbath, the seventh day.
Many leading Rabbis have opposed the division of Archbishop Langton, however today most Bibles are printed in this fashion.