What does Romans 5:8 mean?

This is one of the most loved verses in the Bible, and the high point of a lengthier discussion. In previous verses, Paul clearly showed that salvation is on the basis of faith, not works (Romans 3:21–26). That justification—a declaration of righteousness—brings us peace with God, instead of wrath. This is available only to those who have expressed saving faith, as exemplified by men like Abraham (Romans 4:1–12). Given that hope, suffering in the life of a Christian believer can be meaningful. We are safe to hope in God because He loves us. Paul's point here is that we don't have to take God's word alone that He loves us. We can look at the evidence: While we were still sinners, Christ died for us.

What does it mean that Christ died for us? It means that He died in our place. Because of our sin, we deserved to suffer God's angry judgment. We deserved death. Christ took that judgment for our sin on Himself on the cross. He suffered and died in our place. Paul insists that we should take that act as evidence of God's great love for us, especially since God went first. Jesus died in our place, before we knew we would want Him to do that. He died for us before we'd ever done anything to deserve that love. This is a point Paul made in the prior verse: it takes love to die willingly for someone else, even if they're a "good" person. But we, those who have been saved, were still sinners, and we weren't going to improve. In truth, we had no hope of avoiding God's judgment before Jesus took it for us.

God proved His love for us. That makes Him worth trusting.