1. Scripture tells us that all people have sinned.
2. Scripture tells us that the wages of sin is death. (Romans 6:23). Those wages must be paid. That's why there can be no remission of sin without the shedding of blood, which is saying there can be no forgiveness of sin without death. (Heb 9:22). To overlook sin and allow it to go unpunished would be unjust. But God is a just God and therefore He cannot overlook sin. If God were unjust, he would be denying himself, something the Bible says he cannot do (2 Tim 2:13).
3. Given that all have sinned and that the wages of sin is death, the real wonder is why any of us are still alive! We all deserve to die. The fact that some people have died and we did not is only the mere grace of God in extending the life of those who deserve to die. The fact that God allows some to live into their 80’s, or 90’s or even their 100’s while others only live to 1 or 2 years of age does not make God unjust. If it is pure justice we want, no one would be alive. Praise God for his grace and mercy! He is patient and slow to anger.
4. In times of affliction, God is present just as much as at other times. When Jesus suffered, it was the hand of God that bruised him. God did not merely "stand by" or "look away" while Jesus suffered on the cross. At the cross God himself poured out his own wrath on his one and only Son. Jesus bore the wrath of God on the cross, not the wrath of Satan or the Jews.
5. To rightly understand the depth of the love of God, it is important to understand that Christ's crucifixion was not an accident that God never intended or hoped would not happen. Neither was it merely permitted by God. It was ordained by God. God decreed the death of his Son because He so loved the world that he sent his only begotten son that whosoever believes on him should not perish. The fact that God ordained the cross does nothing to relieve the responsibility of the wicked people who crucified an innocent man.
6. The great wonder of it all is that this death was what we deserved. For those who are Christ's, He bore the wrath of God in our place. At the cross, Christ's blood was poured out as a vicarious substitute for our blood to appease (or propitiate as Rom 3:25 says) the wrath of God. At the cross we see the justice of God in demanding an atoning sacrifice for our sin and the grace of God in providing the spotless Lamb for the sacrifice. The only person that has a right to complain about God's justice for taking a life is his Son, Jesus Christ. But Christ willingly went to the cross. He voluntarily offered himself as a sacrifice.