Christians have baptised from the very earliest times. Baptism is a sign of faith and of the wish to be a full member of the Christian Church. It is also a prayer, inviting God's grace (blessing), life and power into the life of the person baptised.
The first person we know to have baptised in the Christian sense was John the Baptist who was preparing people to hear the message of Jesus. Jesus himself told his followers to use baptism as a sign that a person had converted to Christianity.
The Church baptises in the name of the Trinity: Father, Son and Holy Spirit and has done this for over two thousand years. The formula we use now has changed little from those earliest Christians.