What did Jesus accomplish on the Cross?
He accomplished the completed work He came to do — to live the perfect life that we could not, in full obedience and submission to God the Father and thus fulfill the Law and Prophets, and to offer His life as the perfect offering for man’s sin, to satisfy God’s wrath against humanity. He completed that which the Old Testament sacrifices of animals could never do — a voluntary sacrifice offered once for all time, by the God-man who could take our place since He was fully human yet was fully God and had no sin in Himself, the perfect sacrifice. Through the cross He reconciled man to God, by providing a way that sinful man could come into God’s presence and go to Heaven — a way that satisfied God’s holiness and judgment. As has been said by others, it’s no problem for God to let someone go to hell; the problem is how to let a sinner deserving of hell go to heaven instead. The work of the cross bought Christ a people for His own, those called out of the world.