Note 9 at 1 Cor. 1:25: God is never foolish or weak. Yet, foolish man often perceives Him that way.

Paul had just made reference to how the wisdom of men viewed the crucifixion of Christ as foolishness (v. 23). So, in context, Paul is saying that Christ and His method of salvation through faith in His grace (see note 1 at v. 18, p. 862) is wiser and better than any plan of salvation that man could ever design.