1Cor 6:17

“The soul of Jesus clung to God from the beginning of the creation in a union inseparable and indissoluble, as the soul of the wisdom and word of God, and of the truth and the true light. Receiving him wholly and itself entering into his light and splendor, it was made one spirit with him in a preeminent degree. This is what the apostle promises to those who imitate Jesus.”

“We Are Not Irremediably In Error "It is not true, as some maintain who are led astray by error, that the human being is irremediably dead and can no longer do anything good. A small child is incapable of anything; it cannot run to its mother on its own legs; it tumbles on the ground, cries out, sobs, calls out to her. And she is gentle with it, she is touched to see her baby seeking her so impatiently with so many sobs. It cannot reach her but cries out to her tirelessly, and she goes to it overcome with love, she kisses it, presses it to her heart and feeds it, with unspeakable tenderness. God loves us and he behaves like her towards the soul that seeks him and cries out to him. In the eagerness of that infinite love that is his… He takes hold of our spirit, unites Himself to it, and we become 'one spirit with Him', as the apostle says (I Corinthians 6.17). The soul is linked with the Lord, and the Lord, full of compassion and love, unites Himself to it and it dwells in his grace. Then the soul and the Lord are one spiritually, they form one life, one heart." - "Homily 46"”

“"But he that is joined unto the Lord is one spirit." For the conjunction suffers the two no longer to be two, but makes them both one. Now mark again, how he proceeds by means of the bare terms, conducting his accusation in the names of the harlot and of Christ. Wherefore he saith, "He that is joined to a harlot is one body; but he that is joined to the Lord is one Spirit." For such an one becomes thenceforth Spirit, although a body envelope him. For when nothing corporeal nor gross nor earthly is around him, the body doth but merely envelope him; since the whole government of him is in the soul and the Spirit. In this way God is glorified. Wherefore both in the Prayer we are commanded to say, "Hallowed be Thy Name:" and Christ saith also, "Let your light shine before men, that they may see your good works, and glorify your Father which is in heaven." So do the heavens also glorify Him, uttering no voice, but by the view of them attracting wonder and referring the glory unto the Great Artificer. So let us glorify Him also, or rather more than they. For we can if we will. For not so much do the heaven nor day nor night glorify God, as a holy soul. For as one that gazeth upon the beauty of the heaven, saith, "Glory be to Thee, O God! How fair a work hast thou formed!" so too when beholding virtue in any man: nay, and much more so in the latter instance. For from these works of creation all do not glorify God; but many even assert that the things which exist are self-moving: and others impute to demons the workmanship of the world and providence; and these indeed greatly and unpardonably err: but in regard to the virtue of man, no one shall have power to hold these shameless opinions, but shall assuredly glorify God when he seeth him that serveth Him living in goodness. For who shall help being astonished when one being a man, and partaking of our common nature, and living among other men, like adamant yields not at all to the swarm of passions? when he is injured, and blesses; when he is evil reported of, and praises; when he is despitefully used, and prays for those who injure him; when he is plotted against, and does good to those that fight with him and lay snares for him? For these things, and such as these, will glorify God far more than the heaven. For the Greeks when they behold the heavens feel no awe; but when they see a holy man exhibiting a severe course of life with all strictness, they shrink away and condemn themselves. Since when he that partakes of the same nature as themselves is so much above them, a great deal more so than the heaven is above the earth, even against their inclination they think that it is a Divine power which works these things. Wherefore He saith, "And glorify your Father which is in heaven."”

“See how by the very names of the harlot and of Christ he continues and intensifies the accusation. He says that "he who is joined to the Lord" becomes nothing other than "spirit," since he does nothing carnal — that is, he becomes spiritual. For union with the Lord grants him the sanctification of the Spirit. In these words he also showed how the faithful become members of Christ.”

“Living in the Spirit of the Son, let such a soul recognize herself as a daughter of the Father, a bride or even a sister of the Son, for you will find that the soul who enjoys this privilege is called by either of these names. Nor will it cost me much to prove it, the proof is ready to hand. They are the names by which the Bridegroom addresses her: "I come into my garden, my sister, my bride." She is his sister because they have the one Father; his bride because joined in the one Spirit. For if marriage according to the flesh constitutes two in one body, why should not a spiritual union be even more efficacious in joining two in one spirit? And hence anyone who is joined to the Lord is one spirit with him.”

“You see that even majesty yields to love? So it is, brothers; love looks up to no one, but neither does it look down on anyone. It regards all equally, who love one another perfectly, and in itself it tempers together the lofty and the lowly; not only making them equals, but one. Perhaps you still think that God is excepted from this rule of love; but "he who clings to God is one spirit" (1 Cor 6:17). Why do you marvel at this? He himself was made as one of us. I have said too little: not as one, but one. It is a small thing to be equal to men: he is man. Thence he claims our land for himself, but as a homeland, not as a possession. Why should he not claim it? Thence comes his bride, thence the substance of his body; thence the Bridegroom himself; thence "two in one flesh." If one flesh, why not also one homeland?”

“When a worthy admission has come about together with a holy perception, then the soul is rapt in God, that is, in the beloved. "My Lover belongs to me and I to Him; He browses among the lilies," for the soul already feels the union and is made one spirit with God: "he that is joined unto the Lord is one spirit." And this is the highest thing in the soul: it makes it abide in heaven.”

“Secondly he proves the minor saying: But he who is united to the Lord, namely, by faith and charity, is one spirit with him, namely, because he is united to Him in a spiritual, not a bodily, unity. Hence it says in Rom (8:9): "Anyone who does not have the Spirit of Christ does not belong to him," and in Jn (17:21): "That they may be one in us, as we are one," namely by a connection of the Spirit. And because the body serves the spirit, it follows that our bodies too are members of Him to whom we are united by the Spirit, not of course, by a bodily but by a spiritual union. From the two reasons given above one reason can be formed, namely, that because our body is not destined for fornication but for the Lord in such a way that our members are Christ's members, as he explains later, we should not make them members of a prostitute by fornicating.”