Iglesia ni Cristo rejects the observance of Christmas, Easter, and other popular holidays as pagan in origin and therefore unsuitable for Christian practice. Christmas is presented as a Christianization of pagan winter solstice celebrations, while Easter is understood as derived from pagan spring fertility rites. Neither holiday has biblical mandate or apostolic precedent, and both are considered corruptions of pure Christian faith. Members are discouraged from celebrating these holidays or participating in secular festivities associated with them.

Birthday celebrations are also discouraged or de-emphasized in INC, as they are not considered biblically mandated or spiritually significant. Instead, INC focuses on biblical themes and truths without accommodation to secular or pagan observances. This strict separation from "worldly" holiday celebrations is presented as a mark of INC's doctrinal purity and separation from false Christianity. The emphasis is on biblical doctrine and practice rather than on traditions derived from pagan sources.