More than you might think.
1 Corinthians 1.21
For since, in the wisdom of God, the world through wisdom did not know God, it pleased God through the foolishness of the message preached to save those who believe.
Note that salvation is equated with the knowledge of God.
Not just with being forgiven. Or going to heaven when you die.
But knowing God, being in a relationship with Him and increasing in love for Him through Jesus Christ. Learning to love what God does and to be good stewards of all He has entrusted to us. Working out our salvation into the arena of exceedingly and abundantly more so that we increase in the likeness of Christ. Redeeming the time He gives for seeking His Kingdom and righteousness. Following His example in obedience to God’s Law and making disciples.
Human wisdom and reason will not get you to this. It is foolish and vain to think so.
Only the proclamation of Jesus and His saving work can break through the outer defenses of the soul and plant the seed of faith and the knowledge of God.
And only the ongoing and ever more expansive proclamation of Jesus and His Kingdom can help us increase in the knowledge of God and in our great salvation.