When infants who are adopted become Jewish , it may also be done through the naming ceremony conducted either at home or in the synagogue. In many Reform congregations, this would be considered sufficient ritual conversion for girls and also for a large number of boys. This act, along with Jewish education, would bring the child into the covenant of Judaism in the same manner as a child born Jewish .
We have several possibilities which might be followed in the conversion of this young boy about whom you ask. He should certainly begin to receive some Jewish education. As he is already circumcised, his parents might want to undertake tipat dam. Although tradition would encourage this, we would not suggest it for a child four years old. It would certainly provide a negative initial experience with Judaism . However, tevilah, with an appropriate ceremony, or a Hebrew name bestowed either in the synagogue or at home, would provide a proper initiation into Judaism through something meaningful and understandable to the young boy and his parents.