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Albert Ogier
There was a discussion for years about marriage being from God or from Moses. Jesus settled that by saying "at the beginning" Matt 19:4. It makes little difference to the fact that when Moses gave the law, there was still no tabernacle or temple, no priests. There was no ceremony to go through. It was simply a man and a woman coming together. The ceremony was added later to ask God’s blessing and ask the people to support the couple. There is no thing as sex before marriage, sex is marriage.
Remember Henry 8th. He did not get divorced twice. The first one was an annulment. He and his advisors had to convince the Pope that there had been no sex and therefore there had been no marriage. It was not until much later that the state demanded proof for legal and fiscal reasons that the ceremony became the deciding factor.