One of our great failings is in looking at God and His revelation of Himself with our fallen, human eyes. We project. When He says He is a "jealous God" we judge Him by our creaturely standard of what "jealousy" means. We have been trained to think that "jealousy" and "wrath" are always "negative" emotions, to be avoided, transcended.
But the flip side of jealousy and wrath can be a genuine and healthy sense of love and protectiveness. For instance, David Bowie, who I have been necessarily studying more in depth for my artistic venture, famously had an "open" marriage when he started out in rock'n'roll with his then wife Angie. While "jealousy" nevertheless entered in to it, in the beginning they both were quite proud of the fact that either of them could take on lovers as they wished, outside of their marriage.
It ended in disaster, Bowie himself even admitted later. What kind of love is it that says, "I don't care who you are intimate with, who you are emotional involved with, whatever you do is fine with me"? Neither felt like the other actually loved or cared for them, as shown by the laissez–faire attitude towards their relationship, and so it ended up in wreckage, sadness, anger, tears. Would we rather have a God who did not care what happened to us or where we placed our allegiance? Those who do (not care about God's concerns) similarly end in wreckage, tears and destruction as the gods they pursue instead DO not love them.
God is loving and protective and "jealous" of His children. He does not want them abused, taken away or devoting themselves to others who did not create them. His "jealousy" is perfect, born out of love and care for His vulnerable creations. Same with His wrath. Would you be outraged if someone took your child, abused them horribly and tossed them aside like garbage? If you weren't outraged, "wrathful", it shows that you did not really love them. God's intense wrath is born out of His intense love. His standards are perfect, good, holy--THE BEST is what He wants for His creatures and creation. Anyone or anything that seeks to destroy or corrupt His loving creation will be dealt with because He cares so much! He is not a dispassionate, disconnected, disassociated Buddha sitting in contemplative silence while His children and creation groan under the onslaught of evil and corruption and the entities who foist it.
He will wreak vengeance against those who sully His holy vision and handiwork. How dare they! And the degree of His wrath (shown in events like The Flood, but especially The Crucifixion) show the vast degree of His love and righteous jealousy toward all that is His. Rather than skipping over or marginalizing or attempting to explain away the depictions of His wrath in His Word, we ought see them as the necessary flip-side of His intense and real and determined love, attention and care for His creation.