Infidels.org calls this a contradiction because on the one hand God is called a "man of war" and on the other a "God of peace", as though both statements are diametrically opposed or somehow incompatible.
|“||Exodus 15:3 The LORD is a man of war: the LORD is his name.
Romans 15:33 Now the God of peace be with you all. Amen.
This is no more a contradiction than God saying He gives us peace inside even though we will have tribulation outside.
|“||John 16:33 These things I have spoken unto you, that in me ye might have peace. In the world ye shall have tribulation: but be of good cheer; I have overcome the world.||”|
We have peace in God even though outwardly there is trial, war, and tribulation. God is a God of inward peace and yet a warrior as well. This is no contradiction, indeed some of the great martial artists like Bruce Lee focused on inner peace even as their fighting capabilities were honed to a razor's edge. The concept of God's glory is as aptly stated by John Dryden and characterized by Jeff Bridges in Tron Legacy, "Beware the wrath of a patient man."
- Meritt, Jim (1992). A list of Biblical contradictions. Retrieved from http://www.infidels.org/library/modern/jim_meritt/bible-contradictions.html.