Is God a moral monster for commanding the slaughter of the Canaanites?
No. It was not random 'racially' motivated slaughter, or genocide. It was a just judgement on a people so corrupt and iniquitously evil that parents gave their own babies for ritual murder in the heated statue of Moloch.
Oh, and this world does similarly: about 40 million babies murdered each year by their mothers, for convenience! And some like to think God is a moral monster?
But there's more.
If, as most people hold, a woman has the 'right' to murder her baby, what's the problem with God killing his creatures in judgement when they are as unremittingly depraved and evil as the ancient Canaanites were?
Secondly, for the materialists amongst you, death is a reordering of chemicals. How does that attract any moral value? Wherein lies your disgust at any action in a material world? It's all just atoms. Nothing to see here, folks, no real 'persons' involved, just move along now.
Or maybe you just can't live consistently with your materialism, because it's not true.
Frank Turek addresses this at https://youtu.be/zjBeR6f-NZ8
Willy Craig here: https://youtu.be/9FGv9aOCcyU