A bit of background and context: in Colossians 2, Paul exhorts the believers, "See to it that no one takes you captive by philosophy and empty deceit, according to human tradition, according to the elemental spirits of the world, and not according to Christ" (Col 2:8). The fact that he warns about such a thing tells me that I have an enemy seeking to take me captive by philosophy (the 'wisdom' and religiosity of this world) and empty deceit (making something look rich and desirable that is, in fact, meaningless and harmful). Paul goes on in the next verses to remind the Christians of who Jesus is and what He has done for them: circumcising their hearts, raising them from the dead through faith, and "canceling the record of debt that stood against us with its legal demands" (Col 2:14).
With Christian identity thus established, Paul tells the Christians:
Colossians 2:16-17, 21-22
"Therefore let no one pass judgment on you in questions of food and drink, or with regard to a festival or a new moon or a Sabbath. These are a shadow of the things to come, but the substance belongs to Christ....If with Christ you died to the elemental spirits of the world, why, as if you were still alive in the world, do you submit to regulations--'Do not handle, Do not taste, Do not touch' (referring to things that all perish as they are used)--according to human precepts and teachings? These have indeed an appearance of wisdom in promoting self-made religion and asceticism and severity to the body, but they are of no value in stopping the indulgence of the flesh."
There is an important lesson here if we're going to live in true freedom, and not in bondage to any human (unbiblical) regulations. The Bible lays out clearly that trust in Jesus and an obedient life by the Spirit are what God requires.
The apostles in Jerusalem gave an answer when asked whether Gentile believers should be circumcised and told to keep the law of Moses:
Acts 15:5-14, 19-21
But some believers who belonged to the party of the Pharisees rose up and said, "It is necessary to circumcise them and to order them to keep the law of Moses."
The apostles and the elders were gathered together to consider this matter. And after there had been much debate, Peter stood up and said to them, "Brothers, you know that in the early days God made a choice among you, that by my mouth the Gentiles should hear the word of the gospel and believe. And God, who knows the heart, bore witness to them, by giving them the Holy Spirit just as he did to us, and he made no distinction between us and them, having cleansed their hearts by faith. Now, therefore, why are you putting God to the test by placing a yoke on the neck of the disciples that neither our fathers nor we have been able to bear? But we believe that we will be saved through the grace of the Lord Jesus, just as they will."
And all the assembly fell silent, and they listened to Barnabas and Paul as they related what signs and wonders God had done through them among the Gentiles. After they finished speaking, James replied, "Brothers, listen to me. Simeon has related how God first visited the Gentiles....Therefore my judgment is that we should not trouble those of the Gentiles who turn to God, but should write to them to abstain from the things polluted by idols, and from sexual immorality, and from what has been strangled, and from blood. For from ancient generations Moses has had in every city those who proclaim him, for he is read every Sabbath in the synagogues."
The believers were not (are not) required to keep the Mosaic law, or even to keep a certain day of worship. To begin to believe, practice, and teach otherwise is contra scripture. This is the heart of much of the New Testament teaching on the freedom of the believer.
HOWEVER, many times I have seen Col 2:21 used to excuse behavior or habits that are displeasing to God. This misuse of scripture is along the same lines of "Judge not, man!" Neither scripture can be used as a "proof text" to accomplish your own will, and if you try to use it to that end, you are manipulating the Word of God. Let me give an example: I have seen professing Christians defend violent, sexual movies with passion and incredulity usually reserved for very personal offenses. I have seen the same passion used to defend pot smoking. And what is the battle cry against the person trying to point out the problems in reconciling those things with a Christian life?
"I am so tired of people telling me, 'Do not taste! Do not handle! Do not touch!"
My point is this: God did not give that exhortation so we'd have a license to sin. His desire is for us to walk in truth, and experience true freedom in Him, walking away from the bondage of sin. He admonishes believers not to be goaded into following a deceptive philosophy that will lead them into the bondage they were in before knowing Christ--philosophy that has an appearance of holiness or righteousness, but is dead.
Satan so often brands his routes to enslavement as "Freedom" highways. They are, in fact, the broad road to destruction. Let no one deceive you.
One more passage! Paul goes on to write:
"If then you have been raised with Christ, seek the things that are above, where Christ is, seated at the right hand of God. Set your minds on things that are above, not on things that are on earth. For you have died, and your life is hidden with Christ in God. When Christ who is your life appears, then you also will appear with him in glory.
Put to death therefore what is earthly in you: sexual immorality, impurity, passion, evil desire, and covetousness, which is idolatry. On account of these the wrath of God is coming. In these you too once walked, when you were living in them. But now you must put them all away."
Let us put off the ways of the enemy and put on Christ.