Why do infants receive holy communion in the Orthodox Church?
This is actually the most ancient practice for all the apostolic of East and West. It seems well established that infant baptism was an apostolic ordinance (as indicated by Origen). The mystery or sacrament of initiated included not only baptism (by triple immersion) but also chrismation and the reception of the Eucharist. Hence, one is either in the Church and in Christ or not – there is no partial or fragmentary participation in the Church.