Knowledge and judgment that are motivated by love (Philippians 1:9) are directed very carefully to certain end products that will fulfill our Lord's design and desire for His adopted sons and daughters while they are still on earth.
A repository of facts can be nothing more than a curiosity, and is often an arrogant distraction. A growing intellectual ability must be useful. It is no different in God's kingdom. Our knowledge and judgment must be used to "approve things that are excellent."
Paul's challenge to the Roman church was that they use their minds to "prove what is that good, and acceptable, and perfect, will of God" (Romans 12:2). To his young son in the faith, Paul insisted that Timothy study to show himself "approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth" (2 Timothy 2:15).
The "proving" (testing, affirming) has a twofold goal: that our life on this earth would be "sincere and without offence" and that we would be "filled with the fruits of righteousness." Purity and productivity are earthly spiritual goals that are reiterated many times in the Scriptures. They, of course, are mere reflections of the holiness that our Lord creates in us when we are born again (Ephesians 4:24), but they are nonetheless an often repeated demand for those of us who claim a kinship with Christ Jesus.
The Bible sums it up this way: "But as he which hath called you is holy, so be ye holy in all manner of conversation; Because it is written, Be ye holy; for I am holy" (1 Peter 1:15-16). HMM III http://www.icr.org/article/5950/