I understand now where you're coming from. You believe the OT provides a contrast with the NT. Under the Law we're condemned, demonstrating the need for a Savior. The New Testament demonstrates the Love of God toward mankind once the Sacrifice has been offered on our behalf. Fair enough.
The reason I believe differently than you is because the wrath of God is evident in the NT as well as the OT. Read Acts 5:1-10, for example, which tells the story of Ananias and Sapphira, who were destroyed as punishment for telling a lie. Do you concede that God took their lives?
You believe the OT provides an illustration of God's wrath, while the NT provides an illustration of God's mercy. I believe the OT and the NT alike demonstrate both characteristics of God. How many times was God merciful in the OT? More specifically, how many times was He patient with Israel when they were sinning?
The Atonement has provided the path to redemption. Whoever puts their faith in Jesus Christ is saved from spiritual condemnation. However, I do not interpret this to mean God does not punish us. Ultimately, the biggest difference between us is I do not believe God is all mercy, all the time. I believe the Lord shows mercy upon whom He wants to show mercy and compassion upon whom He wants to show compassion (Romans 9). I also believe God punishes individuals and entire Nations for their wickedness. I believe Ananias and Sapphira were punished for their wickedness.
In other words, I believe that contrast between wrath and mercy still exists! If there were no condemnation whatsoever, would God's mercy seem so gracious to those who receive it? It is a matter of perspective. If there were no darkness, would the light shine so brightly? I believe this is why some people go to hell. The Atonement of Jesus Christ on our behalf certainly has the power to redeem everyone, but God allows some men to go to hell, in order that His glory will be proclaimed.
Do you believe people go to hell?
If so, how is that compatible with your view that God does not express wrath and condemnation?