Isaiah 45:7. God made both The good and the evil of this world.
Other NT verses remind us that all acts are by Him, for Him and through Him.
It is God that commits people to the etenal damnation of hell, not a devil.
What purpose would the devil have, if not merely a tool of God's. The devil cannot oppose God - only perform His bidding. There is no point to a "devil" - which IMO is merely the construct of man's imaginings. Ultimately, with no room for manouvreability the devil is no more than God's handyman (angel of destruction). Therefore an aspect of God's nature.
God is, indeed, graceful, merciful and good - but, also desructive, merciless and evil to boot.
If you wish - we can explore this more in depth?
Thank you, and journey well, sir, always.