Answer
God is peaceful. He wants all mankind to live in peace. He wants that all would become ONE. Just as God and Jesus are ONE. Remember John 3:16. GOD is LOVE and LOVE is PEACE.
God is warlike
Exodus 15:3 The Lord is a man of war.
Psalm 18:34 He teacheth my hands to war.
Psalm 144:1 Blessed be the Lord my strength, which teacheth my hands to war, and my fingers to fight.
God teaches peace to all however believes in defending the weak.