To study the words of Ap. Paul “Set your mind on things above, not on things on the earth”, it is important to understand the broader context of the text; which I have identified to be from Col. 2:6 through Col. 3:17. First because it is long, and secondly because chapter 2 is particularly complicated, we shall make an effort to simplify it by focusing only on the words which are directly related to the subject. That means we shall skip several verses and will reconstruct some of Paul’s complicated expressions, so as to make sense.

Colossians 2:6 As you therefore have received Christ Jesus the Lord, so walk in Him, 7 rooted and built up in Him and established in the faith, as you have been taught, abounding in it with thanksgiving.
…
9 For in Him dwells all the fullness of the Godhead bodily; 10 and you are complete in Him, who is the head of all principality and power. 11 In Him you were also circumcised with the circumcision made without hands, by putting off the body of the sins of the flesh, by the circumcision of Christ, 12 buried with Him in baptism, in which you also were raised with [Him] through faith in the working of God, who raised Him from the dead.
…
19 and not holding fast to the Head, from whom all the body, nourished and knit together by joints and ligaments, grows with the increase [that is] from God.
Change to imperative: – hold fast to the Head, from whom all the body, nourished and knit together by joints and ligaments, grows with the increase [that is] from God.

20 Therefore, if you died with Christ from the basic principles of the world, why, as [though] living in the world, do you subject yourselves to regulations:
Change to imperative: – Therefore, if you died with Christ from the basic principles of the world, do NOT subject yourselves to regulations as though YOU STILL live LIKE in the world

Note on verses 21-23: Here Paul says that the commandments and doctrines of men have an appearance of wisdom in self-imposed religion, false humility, and neglect of the body, but they have no true value (i.e. in regards to the things above); in reality they result in fleshly indulgence.

In other words, the religious works provide a sense of satisfaction to the flesh through observing regulations which are of this world, which are easy for carnal people to do. They give a sense of doing something good for God, but are of no value when it comes to what is of real value, which is what Ap. Paul is trying to explain (in chapter 3).

Colossians 3:1 If then you were raised with Christ, seek those things which are above, where Christ is, sitting at the right hand of God.
2 Set your mind on things above, not on things on the earth.
3 For you died, and your life is hidden with Christ in God.
4 When Christ [who is] our life appears, then you also will appear with Him in glory.
5 Therefore put to death your members which are on the earth: fornication, uncleanness, passion, evil desire, and covetousness, which is idolatry.
6 Because of these things the wrath of God is coming upon the sons of disobedience,
7 in which you yourselves once walked when you lived in them.
8 But now you yourselves are to put off all these: anger, wrath, malice, blasphemy, filthy language out of your mouth.
9 Do not lie to one another, since you have put off the old man with his deeds,
10 and have put on the new [man] who is renewed in knowledge according to the image of Him who created him,
11 where there is neither Greek nor Jew, circumcised nor uncircumcised, barbarian, Scythian, slave [nor] free, but Christ [is] all and in all.
12 Therefore, as [the] elect of God, holy and beloved, put on tender mercies, kindness, humility, meekness, longsuffering;
13 bearing with one another, and forgiving one another, if anyone has a complaint against another; even as Christ forgave you, so you also [must do.]
14 But above all these things put on love, which is the bond of perfection.
15 And let the peace of God rule in your hearts, to which also you were called in one body; and be thankful.
16 Let the word of Christ dwell in you richly in all wisdom, teaching and admonishing one another in psalms and hymns and spiritual songs, singing with grace in your hearts to the Lord.
17 And [whatever] you do in word or deed, [do] all in the name of the Lord Jesus, giving thanks to God the Father through Him.