Apparently Brigham Young taught Adam is Heavenly Father, and that his wife Eve is Heavenly Mother: I tell you more, Adam is the father of our spirits ... our spirits and the spirits of all the heavenly family were begotten by Adam, and born of Eve. ... I tell you, when you see your Father in the Heavens, you will see Adam; when you see your Mother that bore your spirit, you will see Mother Eve.
Was Young teaching this before the plural marriage teachings came about? I know little about the LDS so have no time line to go by.
Was Young teaching this [Adam-God]before the plural marriage teachings came about?
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No. The ‘inner circle’ practiced polygamy before the ‘revelation’ D&C 132 was even given. Polygamy did not become open until after Smith’s death.
So, the teaching of plural marriage (if not the PUBLIC practice) came about before Young started teaching the Adam-God doctrine.
However, it is possible that it was a topic of discussion privately before it became public (like Polygamy), but IIRC the earliest date Young publically taught it was 1873.
Here is a link to more articles that give timelines.