"For this reason we also, since the day we heard it, do not cease to pray for you, and to ask that you may be filled with the knowledge of His will in all wisdom and spiritual understanding"
Before this verse can be expounded, it is important to know "this reason" which Paul gives for why he does not cease to pray for the church of Colosse. Paul gives his reason in verse four, which is that he heard of their faith in Christ and their love for the saints. Such news prompts Paul to pray that the church will be filled with knowledge and wisdom. Zeal without knowledge is dangerous, and according to Hosea 4:6,
"My people are destroyed for lack of knowledge."
The knowledge being spoken of is a knowledge of God.
Therefore, it is important that the Colossian church channel her zeal through the knowledge and wisdom which God has revealed to her. Otherwise, she will be as
"those who, when they hear, receive the word with joy; and these have no root, who believe for a while and in time of temptation fall away (Luke 8:13)."
Every Christian will do well to pay attention to these words which are spoken by Jesus, because "believing" the gospel is an easy thing to do until one is buffeted, outwardly and inwardly, by every manner of trial which the world, the flesh, and Satan can muster. In such trying times, those who have no root will wither, while those who truly believe will be preserved through their knowledge and understanding of Jesus Christ which come by the grace of God.