Perhaps you do not understand because you are looking at "modern religion" and not the "Church" which are the obedient children of God. I must however agree that "modern religion" has become as the Pharisee. Children of God will always recall the mighty hand of God when he is angered.
If you look at the Hebrew, Tyndale, Wyclif, 1611 KJV, Standard KJV; and then look at the scripture you've pointed out, then read the preceding chapter, the chapter your quoting and then the chapter after; things become somewhat clearer.
Exodus 15:3 You have a setting in which God is defending his children at all cost against the Egyptians that would destroy and enslave them.
Isaiah 42:13 Here again when we look at the content in which we are quoting, we find God protecting the obedient from those who would lead them to spiritual destruction and who would destroy them. I am a non-violent man, however I like to think that I love my children to protect them at all cost.
Jeremiah 22:10 The NASB translates " like a dread champion" Go back to the Hebrew, Tyndale, Wyclif, 1611 KJV, Standard KJV, and the NASB; and read the whole content and you'll find a God protecting the obedient.
Psalms 24:7-8 Is part of the songs that is credited to King David. This particular Psalm not only credits God with being "Mighty in Battle" but; Pure of Heart, Not Deceitful" and in reading the preceding chapter and later we find he is also a loving and caring God.
I will agree that God is a mighty warrior, I also would point out that he is merciful, just and true, kind, forgiving and loving.
These things are also thoroughly grounded in scripture, and supported by scripture.
I would like to thank you Rev. Holt for your blogs, I find them insightful, even when I can not concur with them. I truly enjoy your thoughts and opinions.
Rev. Robert Fuller