While you're right in that John Quincy Adams was against slavery, you are, however, wrong in that he was a Founding Father. And while Thomas Jefferson wrote the Delcaration of Independence and was against slavery, he was not a part of the Constitutional Convention to draft it.
However, John Rutledge was a slave-owner, and supported it. He later became Chief Justice after John Jay.
Pierce Butler and Charles Pinkney slipped in the Fugitive Slave Clause into the Constitution that demanded that fugitive slaves escaping to free states be extradited back to the slave owner.
Daniel of St. Thomas Jennifer owned a plantation in Annapolis and instructed that all his slaves be freed 6 years after his death. So he was against slavery too, but only after he could no longer profit from their labor.
While George Mason did find slavery morally objectionable, he only had the strength of his convictions to want to stop the importation of slaves, but not necessarily use the Constitution to force the states to ban slavery. However, it should be noted he was in favor of the disestablishment of the church.
So this proves that the Founding Fathers were not always united in their opinions and beliefs, and some of them actually favored slavery in our nation. So, more likely than not, they were divided in regards to other beliefs as well.