Reading the Old Testament for the first time and currently made it through Numbers. Through the Mosaic covenant, God sounds more like a meglomaniacal power crazed dictator or tyrant who commands respect and will kill anyone at whim for the slightest disloyalty or disobedience- more along the lines of an Idi Amin, a Hussein or a mafia boss. This personality and leadership style is very different than the Jesus of New Testament who didn’t kill anyone, didn’t turn anyone into pillars of salt. He didn’t say Peter you will deny me 3 times and afterward I will kill you for being disloyal. He forgave everyone who was meek and humble and taught love, peace and forgiveness. I guess I grew up as a child of the 70s believing God was more like a 60’s hippy pacifist- “peace and love man”. If Jesus says if you know me you know my father, then why such a contrast in personalities between God of Old Testament and Jesus of New Testament?
There’s a two word answer to your question … the cross. God has many qualities but he can’t express any of them at the expense of any other. It’s either all or nothing with Him.
In the Old Testament we see a righteous God who can’t fully express His love for us because of our sin problem. It kept man from being able to meet His needs for righteousness, and it kept Him from being able to show His love for man. He knew man couldn’t do anything about the problem, so He had to. By dying for all of our sins his needs for righteousness were met and now He’s free to love us. He’s the same God and we’re the same people, but the cross took away the sin problem and changed everything. (Colossians 1:19-20)