"Kant, as I say, invented a new moral argument for the existence of God, and that in varying forms was extremely popular during the nineteenth century.. It has all sorts of forms. One form is to say that there would be no right or wrong unless God existed...
...if you are quite sure there is a difference between right and wrong, you are then in the situation: is that difference due to God's fiat or is it not? If it is due to God's fiat, then for god Himself there is no difference between right and wrong, and it is no longer a significant statement to say that god is good. If you are going to say, as theologians do, that God is good, you must then say that right and wrong have some meaning which is independent of God's fiat, because God's fiat's are good and not bad independent of the mere fact that He made them. If you are going to say that, you will then have to say that it is not only through God that right and wrong came into being, but that they are in their essence logically anterior to God."
Bertand Russell, "Why I am not a Christian", p19; 'The Moral Arguments for Deity'
...if you are quite sure there is a difference between right and wrong, you are then in the situation: is that difference due to God's fiat or is it not? If it is due to God's fiat, then for god Himself there is no difference between right and wrong, and it is no longer a significant statement to say that god is good. If you are going to say, as theologians do, that God is good, you must then say that right and wrong have some meaning which is independent of God's fiat, because God's fiat's are good and not bad independent of the mere fact that He made them. If you are going to say that, you will then have to say that it is not only through God that right and wrong came into being, but that they are in their essence logically anterior to God."
Bertand Russell, "Why I am not a Christian", p19; 'The Moral Arguments for Deity'