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"Therefor what God has joined together, let man not separate."
Mark 10:9
"Anyone who divorces his wife and marries another woman commits adultry against her."
Mark 10:11
"Thou shall not commit adultry"
The VI commandment
"Do not have sexual relations with your neighbors wife and defile yourself with her"
LEV 18:20
"9 Why did you despise the word of the LORD by doing what is evil in his eyes? You struck down Uriah the Hittite with the sword and took his wife to be your own. You killed him with the sword of the Ammonites."
2 Sam 12:9
1 The LORD sent Nathan to David. When he came to him, he said, "There were two men in a certain town, one rich and the other poor. 2 The rich man had a very large number of sheep and cattle, 3 but the poor man had nothing except one little ewe lamb he had bought. He raised it, and it grew up with him and his children. It shared his food, drank from his cup and even slept in his arms. It was like a daughter to him.
4 "Now a traveler came to the rich man, but the rich man refrained from taking one of his own sheep or cattle to prepare a meal for the traveler who had come to him. Instead, he took the ewe lamb that belonged to the poor man and prepared it for the one who had come to him."
5 David burned with anger against the man and said to Nathan, "As surely as the LORD lives, the man who did this deserves to die! 6 He must pay for that lamb four times over, because he did such a thing and had no pity."
7 Then Nathan said to David, "You are the man! This is what the LORD , the God of Israel, says: 'I anointed you king over Israel, and I delivered you from the hand of Saul. 8 I gave your master's house to you, and your master's wives into your arms. I gave you the house of Israel and Judah. And if all this had been too little, I would have given you even more. 9 Why did you despise the word of the LORD by doing what is evil in his eyes?
2 SAM 12: 1-9
Definition of bastard: A man is a bastard if born, first) before the marriage of his parents
Nowhere does it say that if a married person commits adult, they are no longer married in the eyes of the Lord. Period. Look all you want, you wont find it. So the argument that God has "turned his back on this marriage" (or something like that), is completely baseless.
Did Christ him self not say "But I tell you that anyone who looks at a woman lustfully has committed adult with her in his heart" Mat 5:28.
So by your reckoning (adultery=automatic devoice) any man who looks at a woman lustfully is thereby devoiced in the eyes of the Lord? Christ said it himself. You look in lust, you've committed adultery. Doesn't get much planer than that.
We can play dueling scriptures all day long, but your argument will not be advanced by the "they're not really married" angle. It just isn't so.