Let's look at chapter two of Colossians:

1 For I would that ye knew what great conflict I have for you, and for them at Laodicea, and for as many as have not seen my face in the flesh;
2 That their hearts might be comforted, being knit together in love, and unto all riches of the full assurance of understanding, to the acknowledgement of the mystery of God, and of the Father, and of Messiah;
3 In whom are hid all the treasures of wisdom and knowledge.

Sha'ul has never met this group of believers in person, he knows only what he has been told by Epaphras. But he still wishes to send comfort to them for the troubles they are experiencing -- the Colossians are over-run with worldly influences.

4 And this I say, lest any man should beguile you with enticing words.
5 For though I be absent in the flesh, yet am I with you in the spirit, joying and beholding your order, and the stedfastness of your faith in Messiah.
6 As ye have therefore received Messiah Yeshua the Lord, so walk ye in him:
7 Rooted and built up in him, and stablished in the faith, as ye have been taught, abounding therein with thanksgiving.
8 Beware lest any man spoil you through philosophy and vain deceit, after the tradition of men, after the rudiments of the world, and not after Messiah.
9 For in him dwelleth all the fulness of the Godhead bodily.
10 And ye are complete in him, which is the head of all principality and power:

Shaul is beginning to expose the problems the Colossians are facing. The Colossians have been taught Yeshua -- their walk and root is established in Him. Yet various worldly groups are infecting the Colossian assembly. There are those among the Colossians who are putting too emphasis on on worldly matters which take the focus off of Yeshua. But completeness can be found only in Yeshua, since He alone is the head of all powers.

11 In whom also ye are circumcised with the circumcision made without hands, in putting off the body of the sins of the flesh by the circumcision of Messiah:
12 Buried with him in baptism, wherein also ye are risen with him through the faith of the operation of God, who hath raised him from the dead.
13 And you, being dead in your sins and the uncircumcision of your flesh, hath he quickened together with him, having forgiven you all trespasses;

The Colossians are no longer uncircumcised of heart because of sin -- they have been circumcised through Messiah, immersed into Messiah, and risen with Messiah through the power of G-d Who raised Yeshua from the dead. Sha'ul is simply reminding the Colossians of all Messiah has done for them. They are no longer dead in their sins and their uncircumcised flesh but are quickened together with Yeshua and forgiven.

14 Blotting out the handwriting of ordinances that was against us, which was contrary to us, and took it out of the way, nailing it to his cross;
15 And having spoiled principalities and powers, he made a shew of them openly, triumphing over them in it.

Yeshua has paid the penalty for man's transgressions by satisfying the demand for atonement on our behalf. So now the transgressions of the Torah that cried against man are satisfied by Messiah's blood atonement. Hasatan is the accuser -- the one who reminds G-d of man's sin constantly; but now through Yeshua, man's transgression is atoned for and hasatan can no longer accuse man before G-d. Wow! It's like man's sin never even happened -- it's taken away. Yeshua openly and victoriously defeated hasatan, who had wanted mankind to suffer his own penalty of eternal condemnation.

16 Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the sabbath days:
17 Which are a shadow of things to come; but the body is of Messiah.

Now we've already read that false teachers have tried to sway the Colossians away from the truth they learned in Yeshua. Sha'ul has just finished encouraging the Colossian believers, reminding them of their circumcision and life in Yeshua. So the Colossians are to let no man judge them for their faithfulness towards G-d's commands and Holy Days. Sha'ul wisely points out that these convocations were a "shadow" of things to come --- the Hebrew word mikraw means rehearsal! In other words, each Colossian observance is actually pointing to Yeshua Himself -- the one who triumphed on their behalf. So the Colossians aren't to let these false ones judge them (or worse, to persuade them to stop observing the things Epaphras has taught them). They are to stand firm and continue the observance! Like Sha'ul told the Corinthians:

"Purge out therefore the old leaven, that ye may be a new lump, as ye are unleavened. For even Christ our passover is sacrificed for us: Therefore let us keep the feast, not with old leaven, neither with the leaven of malice and wickedness; but with the unleavened bread of sincerity and truth. 1 Corinthians 5:7,8

We are to *keep* the feast! The Holy Days were *always* rehearsals -- they always pointed to Yeshua. And now Yeshua has come, we *continue* to keep G-d's appointed times, but now with greater understanding of Yeshua to whom they pointed!

Let's read on. We see that the Colossians are battling the influence of asceticism:

18 Let no man beguile you of your reward in a voluntary humility and worshipping of angels, intruding into those things which he hath not seen, vainly puffed up by his fleshly mind,
19 And not holding the Head, from which all the body by joints and bands having nourishment ministered, and knit together, increaseth with the increase of God.

The Colossians are warned not to listen to those who are teaching angel worship and 'humility' (possibly self-flaggelation or anything done to humiliate oneself) because the ultimate end of such humility and supposed angel worship is actually vanity. One becomes puffed up in showing how humble he is -- his humbleness works opposite than intended. And man is to have no such vanity because he is not the head of the body but Yeshua is. Only Yeshua is worthy of being the head, and of highest honor, so man is to do nothing extreme which would place himself at the head.

20 Wherefore if ye be dead with Messiah from the rudiments of the world, why, as though living in the world, are ye subject to ordinances,
21 (Touch not; taste not; handle not;
22 Which all are to perish with the using;) after the commandments and doctrines of men?
23 Which things have indeed a shew of wisdom in will worship, and humility, and neglecting of the body; not in any honour to the satisfying of the flesh.

This is the ascetic way -- 'touch not; taste not; handle not.' Man is not to deny his body its basic needs (like affection, foods, conjugal needs, etc.). By making normal bodily needs a thing of distaste -- man eventually becomes obsessed about his lack. When basic needs are deliberately denied, one doesn't become closer to G-d; he instead becomes obsessed and focused totally on his own deprivation. Ascetisism teaches that all fleshly things are sinful -- but many fleshly needs are not sinful at all. Though they can certainly become sinful when used to gain leverage with G-d by wrongly manipulating the human body by denying the body's basic needs. Yeshua is the overcomer of the flesh -- not asceticism. With asceticism, the emphasis is wrongly placed in man's power over his own flesh instead of Yeshua's power.

Chapter 3:1 If ye then be risen with Messiah, seek those things which are above, where Messiah sitteth on the right hand of God.
2 Set your affection on things above, not on things on the earth.
3 For ye are dead, and your life is hid with Messiah in God.
4 When Messiah, who is our life, shall appear, then shall ye also appear with him in glory.