Baptists are individuals who comprise a group of Christian denominations and churches that subscribe to a doctrine that baptism should be performed only for professing believers (believer's baptism, as opposed to infant baptism), and that it must be done by complete immersion (as opposed to affusion or sprinkling). Other tenets of Baptist churches include soul competency (liberty), salvation through faith alone, Scripture alone as the rule of faith and practice, and the autonomy of the local congregation. Baptists recognize two ministerial offices, elders and deacons. Baptist churches are widely considered to be Protestant churches, though some Baptists disavow this identity.