you asked for Bible doctrine, Bible teaching on the doctrine of Marriage.
These are doctrinal statements in the Bible. Commands. Teaching. Doctrine.
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Marriage -
Genesis 2.(for those that believe the Bible is reliable) Gen 2:22-24 ... Marriage between 1 man and 1 woman.
21 And the Lord God caused a deep sleep to fall on Adam, and he slept; and He took one of his ribs, and closed up the flesh in its place. 22
Then the rib which the Lord God had taken from man He made into a woman, and He brought her to the man.
23 And Adam said:
This
is now bone of my bones
And flesh of my flesh;
She shall be called Woman,
Because she was taken out of Man.
24 Therefore
a man shall leave his father and mother and be joined to his wife, and they shall become one flesh.
Matt 19:4-7
4 And He answered and said to them, Have you not read that He who made
them at the beginning made them
male and female, 5 and said, For this reason
a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh? 6 So then, they are no longer two but one flesh. Therefore what God has joined together, let not man separate.
Mark 10:6-9
6 But
from the beginning of the creation, God
made them male and female. 7 For this reason a man shall leave his father and mother and be joined to his wife, 8 and the two shall become one flesh; so then they are no longer two, but one flesh. 9 Therefore what God has joined together, let not man separate.
1 Tim 3:2
2 A bishop then must be blameless,
the husband of one wife, temperate, sober-minded, of good behavior, hospitable, able to teach;
As far as I know the RCC Doctrine on marriage agrees with these particular Bible verses - so I am not sure why you are putting this forward as something the Bible may not have much to say about.
So, you discount the episodes in the OT where men have many wives? Doesn't the Bible actually support marriage to multiple wives?
It's not a question of whether we agree or not. Where is it in the Bible? Doesn't the Bible support polygamy as well?
And what of pro-life doctrine?
"The two shall become one" is the Gen 2 original form and it is the one Christ affirms in the Gospels.
This is incredibly explicit in the text.
The fact that the Marriage doctrine can be abused in some fashion does not establish an "edit" to the word of God as even NT authors argue for going back to the original form.
The Bible is clear - just when some would need it to be unreliable as the standard of measure.
in Christ,
Bob