The message puts a personal question to every hearer: not what the world says about Jesus, or even what the church says, but who is Jesus Christ to you? Paul’s word about the cross is foolishness to those who are perishing, but to those being saved it is the power of God, and that is the dividing line the whole message works from, whether the cross is nonsense or the very power that saves.
Romans 5 answers why the cross matters: while we were still weak, still ungodly, still sinners, Christ died for us, demonstrating God’s own love toward us. Having now been justified by his blood, we are saved from wrath through him and reconciled to God. That gift stands against the wages sin always pays, death, because the free gift of God is eternal life in Christ Jesus our Lord.