The core christian message is that God is perfectly just in his nature that no sin will be overlooked but will be punished. God acknowledges our human nature that we are fallible and will fall short of his glory and suffer in our sin, so in order for justice to be complete God came down from his majesty in heaven and entered creation to eventually give his life on the cross as our punishment so that we might be free of the consequences of sin in the world and that we will be reconciled back to God. He lived the life we should have lived and died the death that we should have. Out of his love and mercy for us he redeemed us back into himself that by him paying our debt, we will not perish but have eternal life with our heavenly father. God made a way for us back to himself by paying our debt so that we might be free.
"Jesus said to her, “I am the resurrection and the life. He who believes in Me, though he may die, he shall live." - John 11:25