We only live in the temporary, so that's the only time that is required for morals to be binding. The morality of 500 years ago is not the morality of today, nor should it be. We aren't eternal, so morals don't have to be. They are as transitory as our lives are.
Not true...morals laws are the same as they always were with God...the laws you're talking about that have changed are not considered moral laws...