Charles Ellicott Commentary 1 Corinthians 1:23

"but we preach Christ crucified, unto Jews a stumblingblock, and unto Gentiles foolishness;" — 1 Corinthians 1:23 (ASV)

But we preach.—The gospel of Christ crucified made its way by those very qualities which they regarded as “weakness and folly,” vindicating itself as “the power of God,” more mighty than any “sign” a Jew might ask for; and “the wisdom of God” surpassing any merely intellectual “wisdom” which a Greek might desire.