Paul prays that God will fill them with knowledge, understanding, and wisdom. He wants them to have the facts (knowledge), be able to apply the facts to their own lives (understanding), and to make choices that demonstrate Godliness (wisdom). I think it is interesting that Paul prays for what God is already anxious to give. Prov. 2:6, 10; 9:10; 24:3-4.
It appears that, in combination, they produce a measure of fruitfulness, growth, strength, power, endurance, patience, thankfullness, and joy.
A Christian disciple desires to live a life that pleases God and Glorifies Him. All of these characteristics should be evident in response to the fact that He has rescued, redeemed, forgiven, and welcomed us into the kingdom of His Son.
If any are missing, it will reduce the effectiveness of our witness and indicate that we need to strengthen our relationship with Him.