"The cross is the danger signal to you. It warns you that if God spared not His only Son, He will not spare you. It is the lighthouse set on the rocks of sin to warn you that swift and sure destruction awaits sinners if you continue to rebel against the Lord. Hell is an awful place, or Jesus had not needed to suffer such infinite agonies to save us from it.
It is also fairly to be inferred that out of this danger only Christ can deliver the ungodly, and he only through his death.
If a less price than that of the life of the Son of God could have redeemed men, he would have been spared. When a country is at war, and you see a mother give up her only boy to fight her country's battles-her only well-beloved, blameless son-you know that the battle must be raging very fiercely and that the country is in stern danger: for, if she could find a substitute for him, though she gave all her wealth, she would lavish it freely to spare her darling. If she were certain that in his heart a bullet would find its target, she must have a strong love for her country, and her country must be in dire necessity ere she would bid him go. If, then, "God spared not his Son, but freely delivered Him up for us all," there must have been a dread necessity for it. It must have stood thus: die he, or the sinner must, or justice must; and since justice could not, and the Father desired that the sinner should not, then Christ must; and so he did. Oh, miracle of love!"
-Charles H. Spurgeon from the sermon For Whom Did Christ Die? 1874