Now, communion is the mutual communication of such good things as wherein the persons holding that communion are delighted, bottomed upon some union between them.
Our communion, then, with God consists in his communication of himself unto us, with our returning unto him of that which he requires and accepts, flowing from that union which in Jesus Christ we have with him. And it is twofold:—
1. Perfect and complete, in the full fruition of his glory and total giving up of ourselves to him, resting in him as our utmost end; which we shall enjoy when we see him as he is;—and,
2. Initial and incomplete, in the firstfruits and dawnings of that perfection which we have here in grace; which only I shall handle.
It is, then, I say, of that mutual communication in giving and receiving, after a most holy and spiritual manner, which is between God and the saints while they walk together in a covenant of peace, ratified in the blood of Jesus, whereof we are to treat. And this we shall do, if God permit; in the meantime praying the God and Father of our Lord and Saviour Jesus Christ, who hath, of the riches of his grace, recovered us from a state of enmity into a condition of communion and fellowship with himself, that both he that writes, and they that read the words of his mercy, may have such a taste of his sweetness and excellencies therein, as to be stirred up to a farther longing after the fulness of his salvation, and the eternal fruition of him in glory.
– John Owen –
from Of Communion With God, volume 2 of Works, pages 8-9