Christians celebrate baptism as a ritual that either symbolizes the removal of sin or washes away actual sins. Babies and infants usually are the recipients of a baptism, but adults entering the faith also go through the event. Certain churches only will conduct a baptism when the recipient reaches an age that allows the individual to understand the significance of the event and to make a profession of faith. A person can be baptized through immersion in water or by having water sprinkled or poured over the top of his head. Certain churches insist that baptisms be performed by clergy, while others allow lay persons to do it.