How did you write the holy book?

jesus:

how did you lead people out of egypt during the exodus?

moses:

why did you write the five pillars and why are important to islam?

muhammad:

Moses wrote most of the beginning of the Old testement. The prophets wrote their books too. John wrote Revelations and the book of Johns, Paul wrote the books of the New Testemant towards the back, Matthew, Mark, Luke, and John wrote their own books that are called by their own names

Moses led the people out of the desert through the grace of GOD, and had met many hardships along the way. Because he failed to obey the Lord at some key points, he was not allowed into the promise land.

5 pillars of Islam: 
Shahada: Faith
Salat:Prayer
Zakat: Charity
Sawm: Fasting
Hajj: Pilgrimage to Mecca

hope this helps