The spiritual wisdom and spiritual understanding of which Paul speaks in Colossians 1:9 consists in this: the Christian using the mind, using the intelligence, to bring together various aspects of our knowledge of God's general will as revealed in God's Word, and bringing that combined knowledge to bear on a specific situation.
The specific will of God for any given situation will always agree with the total body of truth that God has set down in His Word. The better you know God's Word, the better you will know God's general will. And the better you know God's general will, the easier it will be to discern His specific guidance in your daily life.
In Colossians 1:9 Paul is praying that the Colossian believers will have that spiritual intelligence.
Christian, that is what God wants you to have.
God doesn't ask you to put your mind in mothballs when you become a Christian. He doesn't ask you to put your intellect in the deep freeze. God doesn't place a premium on ignorance.
Believing on the Lord Jesus Christ liberates Christians to use their minds in a way that the unbeliever can't even understand.
And God's Word equips believers to do that. It is God's Word that equips the Scripture-driven Christian, and the Scripture-driven church. God wants you to use your mind, driven by Scripture, illuminated by the Holy Spirit, to live a godly and fruitful life for His glory. And God wants this for every Christian, not just some elite group.