Isn't that making marriage mystical?
1 Corinthians 6:15-17 is Bible.
I don't know what you mean, about making marriage mystical.
This is how I see that scripture:
God designed marriage to join two humans into one FLESH. Not spirit.
Too many Christians try to make marriage a spiritual union. It isn't.
A husband and wife may be joined in marriage "in the Lord", but that still does not make them one spirit.
They can be joined together as brother and sister in deep spiritual union, as all believers are, in fellowship in Christ, in the unity of the Spirit. But this only comes through time spent in deep fellowship and prayer. It doesn't happen by virtue of the marriage union.
You see, God said in Malachi 2:15
"And did not he make one? Yet had he the residue of the spirit..."
God joined two into one, but reserved for himself that which is not joined together.
He reserves to Himself the 'residue' (leftover part) which is the spirit of each person.
This is why if a widow remarries, it's not adultery--because the marriage does not exist in the spirit realm.
And this is also why a wife cannot hide behind her husband at the Judgment. She will be held accountable for her own conscience, no matter what her husband asked her to do. Remember Sapphira of Acts 5? She was not excused from her lie, because of the 'spiritual headship' of her husband. God expected her to stand up to Ananias, and refuse to do his bidding!"
God reserves for Himself, the spirit of each person.
And just as humans are joined in marriage, and the wife receives life from her husband, to conceive...
Even so, God wants us to be so intimately in deep fellowship with Himself, on a spirit-plane.
He wants us to pray constantly, as if it were more important to us than breathing, than eating, than drinking water.
When someone falls in love, it changes their appetite, their sleeping patterns, and their entire way of thinking.
God wants this kind of relationship with us.
He wants us to fall in love with Him, and seek His presence and His voice constantly.
When this happens, we change completely.
And when we fall out of love with Him, it's because we have left our first love.
We choose to seek other fulfillment, outside of Christ.
And we get our eyes on the idols of this world. Sports. Money. Success. And earthly romance.
But those things can never fill the spirit.
And for a Christian, it's spiritually cuckolding our heavenly Bridegroom.
So we think He doesn't see?
Do we think He doesn't care?
He cares just as much as any earthly bridegroom would care, to find his betrothed is having an affair on the side!
Those who leave their first love, become lukewarm.
And Jesus says He will spit them out like disgusting water.
Many think they are ready for death, because they "prayed a prayer" once, and "accepted Jesus".
But John says that if we say we have fellowship with Him, and do not walk in the light, we are lying.
So, yeah.
He who is joined to the Lord is one spirit.
Like marriage.