What has God accomplished by presenting Christ

God has shown His righteousness with respect to the sins that have been committed previously. He has provided this means of demonstrating His righteousness to people, while at the same time, in His forbearance, "passing over" the sins that men have practiced.

In the cross God has demonstrated both Divine righteousness and Divine mercy. Divine justice has not been harmed and a way has been provided for the repentant, believing sinner.