Colossians 1 & 2

Paul tells the saints of Collose -

"For this cause we also...do not cease to pray for you, and to desire that ye might be filled with the knowledge of his will in all wisdom and spiritual understanding..." (New Testament Colossians 1:9)

Paul's desire was that the saints would be guided by the Holy Ghost in coming to know and understand the will of God concerning them. In other words, that they would come to know the will of God by revelation. Which such revelation is a mystery to those who never experience the spiritual things of God -

"Even the mystery which hath been hid from ages and from generations..." (New Testament Colossians 1:26)

"...but now is made manifest to his saints..." (New Testament Colossians 1:26)

Which mystery is given -

"To whom God would make known what is the riches of the glory of this mystery among the Gentiles; which is Christ in you, the hope of glory:
28 Whom we preach, warning every man, and teaching every man in all wisdom; that we may present every man perfect in Christ Jesus..." (New Testament Colossians 1:27 - 28)

The mystery, hope, and riches of his glory are given -

"That ye might walk worthy of the Lord unto all pleasing, being fruitful in every good work, and increasing in the knowledge of God;
11 Strengthened with all might, according to his glorious power, unto all patience and longsuffering with joyfulness;
12 Giving thanks unto the Father, which hath made us meet to be partakers of the inheritance of the saints in light:
13 Who hath delivered us from the power of darkness, and hath translated us into the kingdom of his dear Son:
14 In whom we have redemption through his blood, even the forgiveness of sins:" (New Testament Colossians 1:10 - 14)

This spiritual understanding or mystery includes a knowledge of the Savior that becomes clear as we ponder -

"Who is the image of the invisible God, the firstborn of every creature:
16 For by him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they be thrones, or dominions, or principalities, or powers: all things were created by him, and for him:
17 And he is before all things, and by him all things consist.
18 And he is the head of the body, the church: who is the beginning, the firstborn from the dead; that in all things he might have the preeminence.
19 For it pleased the Father that in him should all fulness dwell;
20 And, having made peace through the blood of his cross, by him to reconcile all things unto himself; by him, I say, whether they be things in earth, or things in heaven.
21 And you, that were sometime alienated and enemies in your mind by wicked works, yet now hath he reconciled
22 In the body of his flesh through death, to present you holy and unblameable and unreproveable in his sight..." (New Testament Colossians 1:15 - 22)