One of the Vespers’ readings for the Feast of the Meeting of the Lord includes these words from Isaiah 6:5-7 –
So I said: “Woe is me, for I am undone! Because I am a man of unclean lips, and I dwell in the midst of a people of unclean lips; for my eyes have seen the King, the Lord of hosts.” Then one of the seraphim flew to me, having in his hand a live coal which he had taken with the tongs from the altar. And he touched my mouth with it, and said: “Behold, this has touched your lips; your iniquity is taken away, and your sin purged.”
Several Orthodox commentators through the centuries saw Isaiah’s words as a reference to or prophecy of Holy Communion. Indeed, some Orthodox prayers before and after Communion reference the Eucharist as being that heavenly coal which takes away our sins and iniquities. Certain forms of piety liked the idea of the burning coal as purging (burning away) our sins—rather than Christ taking upon Himself the pain of sin and/or our guilt, we still have to suffer for our sins (have them purged, burning out of us). No free salvation in this piety, you have to pay for your sins. Not all Eucharistic piety advocates the need for the sinner to suffer, some of it actually is very grateful for the grace freely given to us by Christ. So Hieromonk Gregorios says:
Through Holy Communion, the Christian receives into himself the true Light. His soul is united to Christ, the Sun of righteousness. His intellect is ‘wholly intermingled with God and illumined through and through by the divine light’. For the person who has partaken of Him, Christ becomes:
Light and peace and joy, life, food and drink,
clothing and cloak, a tabernacle and divine dwelling…
a sun that truly never sets, a star that ever shines,
a lamp shining forth within the House of the soul.
We have received into our souls not simply ‘some ray of light, but the very orb’ of the sun. By grace we have become suns attending upon the one unique Sun. For Christ, ‘having embraced all things with His illumining power, gives to those who are worthy perpetual light, and makes them new suns.’ (THE DIVINE LITURGY, p 300)
Sometimes Orthodox piety embraces the notion that you have to make yourself worthy to receive Christ in Communion. The reality is it is Christ who takes away our sins/guilt and it is He who makes us worthy of heaven, not our pious activities. We don’t make ourselves worthy of Christ, rather Christ makes us worthy of heaven/paradise. For this, we are thankful (eucharistic). It is God who freely gives us the coal, the Body of Christ, which takes away our iniquities and pardons our sins. And God does this in His love for us, while we are still sinners. We don’t make ourselves righteous or worthy to partake of Christ, rather we humbly accept what Christ has done for us and offers to us. Christ doesn’t react to us sinners, rather He loves us and draws us near to Himself. He acts towards us in love, rather than reacting to our sins.
In the fear of God, with faith and with love, draw near. (Exhortation to the faithful at the Liturgy to approach the chalice)
Submit yourselves therefore to God. Resist the devil and he will flee from you. Draw near to God and he will draw near to you. (James 4:7-8)