The Church of South India is a trinitarian church that draws from the traditions and heritage of its constituent denominations. The basic creeds of the Church of South India are the Apostle's Creed and the Nicene Creed of 381 AD.

The CSI practises infant baptism for children born in Christian homes. For others, believers or adult baptism is given. Baptized children are members of the church and share in the privileges and obligations of membership so far as they are capable of doing so.

The full privileges and obligations belong to those who, after attaining to years of discretion, receive confirmation of their baptism. Normally, members are confirmed by the laying on of hands by a bishop. Confirmation may also be given by a presbyter authorized to do so.