The Church of South India (CSI) is a united Protestant Church, predominantly following high liturgy, and is the second-largest Christian church in India based on the number of members. It is the result of union of a number of Protestant mainline denominations in South India after independence. Most of the churches in this denomination are Tamil churches and are widely spread across Tamil Nadu. That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me.'