“God chose what is low and despised in the world, even things that are not, to bring to nothing things that are” (v28). The idea of God as Savior wasn’t new for the Jews or all that radical for Gentiles, who called their leaders “saviors”. The radical part was how God saved, and whom: Jesus was low and despised and suffered on a cross to achieve victory for everyone, even pagans; this was a “stumbling block” and “foolishness” (v23). It was a plan that “no human being” would have invented (v28).
As humans, we tried (and failed) to find wisdom and goodness on our own. By faith, Jesus Christ “became to us” wisdom, righteousness, holiness, and redemption (v30).