Let us say that god exists, and that the old testament is not just another bronze age text, but an accurate account of the existence of a very powerful being and his doings.
But why does the fact that he is powerful mean that I should agree with his moral values? In fact, I very much disagree with the moral values in the old testament.
Some examples:
“A bastard shall not enter into the congregation of the Lord: even to his tenth generation shall he not enter into the congregation of the Lord”
(Deuteronomy 23:2)
In my eyes, its not the boys fault that he is born out of wedlock, but in gods eyes its enough to damn him, and his descendants.
“Samaria shall become desolate; for she hath rebelled against her God: they shall fall by the sword: their infants shall be dashed in pieces, and their women with child shall be ripped up” (Hosea 13:16)
Dashing infants to pieces?!
“And it came to pass, when king Hezekiah heard it, that he rent his clothes, and covered himself with sackcloth, and went into the house of the Lord. . . . And Isaiah said unto them, Thus shall ye say unto your master, Thus saith the Lord, Be not afraid of the words that thou hast heard, wherewith the servants of the king of Assyria have blasphemed me. . . . Then the angel of the Lord went forth, and smote in the camp of the Assyrians a hundred and fourscore and five thousand: and when they arose early in the morning, behold, they were all dead corpses”
(Isaiah 37:1-36)
Some servants from Assyria talks badly about god, and he kills 185.000 of the assyrians.
I could of course go on. Each bible passage is more morally reprehensible than the next, in my view.
If you lived in nazi germany, I believe that the most moral action would be to rebel against the evilness, and not obey orders, even if that might kill you. In the same way, is it not the most moral action to disobey this god, even if he might kill you for it?