The key question in Christianity is, Why the cross? Why did Jesus die? Erickson offers these five implications of the substitutionary death of Christ:
1. It confirms the biblical teaching of the total depravity of humans.
2. It demonstrates both the love and the justice of God in a perfect unity.
3. Salvation comes from the pure, sovereign grace of God.
4. The believer can be secure in the grace of God.
5. We are motivated not to neglect so great a salvation that came at such a great cost.
- Ericson, Christian Theology, 822-823
-taken from "Introduction to Evangelism" by Alvin Reid