1. Why do you baptize people? 

To follow Christ's example. 

At that time Jesus came from Nazareth in Galilee and was baptized by John in the Jordan (Mark 1:9).

To obey Christ's command. 

Then Jesus came to them and said, All authority in heaven and on earth has been given to me. Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age (Matt 28:18-20).