"For those who eat and drink without discerning the body of Christ eat and drink judgment on themselves." 1 Corinthians 11:19
The standard Orthodox understanding of this seems to be that you should not receive Communion when you are "living in sin" or have committed some sin unconfessed. This is often extended to other sacraments as well, including to reception into the Church.
I would like to hear more of an explanation of this from an Orthodox standpoint.
I know Lutheran pastors that would say that if that is the standard- sinlessness, for receiving the Eucharist then it has never been a certain means of grace. Most mainline scholars believe the above passage is a warning to not be a glutton at the agape meal and ignore poor people in the congregation.
Of course the Eucharist should be approached with appropriate dignity but the asceticism with which some approach the Eucharist seems to be one difference I have with Orthodox custom/tradition. It's especially telling that the majority of Orthodox in Russia have never received communion. I can only guess this teaching somehow contributed to the practice of infrequent communion.