What does 1 Corinthians 1:29 mean?

Nobody gets to stand before God and boast they were wise and strong enough to make it into His presence. Period. In fact, wisdom and knowledge can only lead us to understanding of truth (James 2:19); it does not force us to trust in that reality (Romans 1:18–23). Knowledge of God is useless unless a person seeks to know and love God.

Paul has identified two primary groups of people existing in the world of his day. Those who are "somethings" and those who are "nothings." The somethings, by the measure of society, were wise, well-educated, wealthy, respected, and held positions of social standing. For the most part, these somethings had rejected the gospel message that faith in a crucified Christ is the only way to become right with the one, true God.

The nothings, on the other hand, were the disposable, replaceable people in human terms. They had little hope of ever increasing their position in society. They received little respect or recognition.

God chose mostly from among the nothings those who would believe in Christ crucified. Since He is the one who chose them, they will not boast before Him on the day of judgment about their own wisdom and strength to believe in Jesus. They will know they received their faith as a gift.

More importantly in God's eyes, all the somethings will see that their rejection of Christ was not wise or strong or brave. They will understand that it is the reason they have become nothings before God. There will be no boasting.

God takes with deadly seriousness any rejection of His offer to come to Him in humility through faith and Christ.