It's all about having to face a holy, righteous God and having to answer to that God. People know what God has said about free choice, and they hate the idea that there is this sovereign "God" who reigns over them and over the known and unknown universe, and that this "God" has the unmitigated gall to tell them that there is something wrong with them and, apart from Him and His Son's atoning death on the Cross, there is a price to pay for being on the wrong side of free will.
It's just so much easier and comforting to delude oneself into believing that God is a liar, the Scriptures are a myth, and a person can live his life as he chooses, rejecting God, with no consequences.
“a person can live his life as he chooses with no consequences.”
Actually, whether one believes in God or not, there will be consequences if one does not live an honorable and ethical life in relation to others. Perhaps it is even harder to live such a life if one behaves with principles without doing so because big, bad daddy is standing over you ready to clobber you with everlasting torment.