1:23 Christ crucified was a stumbling block to Jews, who expected a political savior, and foolishness to Greeks, who considered anyone who would be crucified of no account.
1:26-31 Not only in the message of the cross foolishness to the perishing (v. 18), God uses those who would commonly be considered foolish, weak, and of no consequence to convey that message. An illustration of this truth was their own church group, which did not include many wise, mighty or noble (v. 26). God's purpose is to exclude all boasting in self (v. 29).
1:30 righteousness of justification. sanctification. Present, progressive sanctification. redemption. Future glorification."
The Ryrie Study Bible [New American Standard Bible], p. 1414