Once upon a time there was this land. Some people came from other lands (mostly Europe) and took the land from the people who had been living there. The people who took the land called it manifest destiny. They said that God said that it was ok. When the people who had been living on the land resisted, the people who came and took the land killed a lot of them and did really bad things to all of them. The people who came and took the land said that this was ok because God said it was ok. Then, the people who took the land brought people from still another land (mostly Africa) and made them work for nothing (and a lot of other bad things). It was called slavery. The people who brought the other people from another land said that this was ok because God said that it was ok. After a long, long time, some of the people who were the children of the children of the children of the people who came and took the land decided that making people work for nothing (and a lot of other bad things) was wrong. One of the people who decided slavery was wrong signed a paper (The Emancipation Proclamation) that said making people work for nothing (and a lot of other bad things) was wrong, so stop it.
Some other people who were the children of the children of the children of the people who came and took the land still believed that God said it was ok to have slaves (if they came from another country).
The two sides could not agree about what they should do so they had a big fight. The people who believed it was wrong to make people work for nothing (and a lot of other bad things) won the fight and it was no longer ok (legal) to make people work for nothing (and a lot of other bad things).
After a long, long time, some of the people who were the children of the children of the children of the people who fought about whether or not it was ok to make people work for nothing (and a lot of other bad things) had a new problem.
Some of the women (and some of the men) thought that women should be able to vote. Some of the men (and some of the women) thought that was a bad idea. The people who thought that the idea of women voting was a bad idea believed that God said it was ok to treat women as though they were property. They had a big argument. The women and men who thought that women should be able to vote won the argument (19th Amendment).
After a quite long time, some of the people who were the children of the children of the people who argued about whether or not women should be able to vote noticed that the children of the children of the children of the children of the people who were made to work for nothing (and a lot of other bad things) were still being treated with great disrespect because of the color of their skin.
Some of the people who noticed this decided that the people who were being treated with great disrespect because of the color of their skin should be treated equally. Some of the other people who were children of the children of the people who argued about whether or not women should be able to vote believed that the it was ok to treat people with great disrespect because of the color of their skin. They believed that God said it was ok. They had a big argument. The people who believed that people should be treated equally no matter the color of their skin won the argument (Civil Rights Act).
We landed on the moon.
After a long, long time, one of the children of the children of the people who argued about whether or not people should be treated equally regardless of the color of their skin became POTUS. There were (are) a lot of people who did not like that because they still believe that people with light skin are better than people with dark skin.
About that same time, some of the children of the children of the people who argued about whether or not people should be treated equally because of the color of their skin decided that two people of the same sex should be able to marry, and that love between two women, or love between two men, or being a gender on the inside that does not match a sex on the outside, should not be a reason to treat someone as less than. The POTUS said he thought so too, not so much at first, but later.
Some other children of the children of the people who argued about whether or not people should be treated equally because of the color of their skin believed that it was ok to deny marriage to two people of the same sex; and that love between two women, or love between two men, or being a gender on the inside that does not match a sex on the outside, is a good reason to treat someone as less than because God said it was ok.
They had a big argument. The argument is still going on. Every day, more and more people realize that love between two men, or love between two women, or being a gender on the inside that does not match a sex on the outside, is ok. And although I think God says it is ok, it doesn't really matter whether God says so or not. It's just ok.
There are a lot of other moments in U.S. history (immigration, sexism, ableism, classism, etc.) that I could have added to this history, but there was not enough room to include all the things that have happened (and are happening) in this country because someone believes God says so.
Now, some of these same children are saying that it is ok to not feed the hungry, and it is ok to not help the poor, and it is ok not to care for the sick, and it ok not to welcome the stranger, because they believe that God said so.
God did not say that. End of story.