There are so many things here - let me try to take them one at a time.
The idea of the OT Ceremonial law and system being a shadow occurs several times in the NT:
- Col 2:17 - These [religious festival and temple rites] are a shadow of the things that were to come; the reality, however, is found in Christ.
- Heb 8:5 - They serve at a sanctuary that is a copy and shadow of what is in heaven. This is why Moses was warned when he was about to build the tabernacle: "See to it that you make everything according to the pattern shown you on the mountain."
- Heb 10:1 - The law is only a shadow of the good things that are coming--not the realities themselves. For this reason it can never, by the same sacrifices repeated endlessly year after year, make perfect those who draw near to worship.
Thus, the stated purpose of the Jewish ceremonial system was as a teaching device to inculcate the plan of salvation (Heb 9:8, 9, 11-14, 10:1, Col 2:16, 17) and had no salvific function (Heb 9:9, 10:4, Ps 51:16, 17, 1 Sam 15:22). That is, it used symbols to teach about the coming Messiah. When Messiah arrived and offered sacrifice for sin and the example of the exemplary life, the ceremonial system’s usefulness ceased to exist.
Thus, the ceremonial system was merely a "shadow" or "type" of things (then) yet future; ie, "to come".
Even in Old Testament times, the ceremonial system had been misunderstood and abused and did not provide propitiation but only symbolized the sacrifice of Jesus (yet to come), eg, Isa 1:10-17, Ps 40:6-8, 51:16, 17, 1 Sam 15:22, Hos 6:6, Prov 15:8, 21:3, Jer 6:20, Micah 6:6-8, etc. Jesus used some of these verses to teach the superiority of the moral and ethical requirements over the ceremonial rules. Matt 9:9-12, 12:2-8, 9-14, 23:23, 24, Mark 12:33. Therefore, in New Testament times, after the reality of Jesus had come, its value was gone.
When Jesus died on the cross, the ceremonial system was finished and the temple curtain dividing the Holy from the Most Holy Place was torn in two from top to bottom (Matt 27:51, Mark 15:38, Luke 23:45, see also 2 Cor 3:13-16) to symbolise this. Jesus became the High Priest of the New Covenant (Heb 4:14-16) and fulfilled the Levitical Covenant. Col 2:16, 17, Gal 4:10, Heb 9:10, Rom 14:17, (comp Isa 1:13, 14) explicitly make these ceremonial laws redundant.
Jesus is the high priest of the New Covenant Heb 4:14-16, 5:10, 7:23-28, 8:1, 2, 9:1-28, 10:1-18. Thus, Jesus inherits and was the fulfilment of the Levitical Covenant (See Mal 3:1). Jesus did this in several ways as well such as:
- Jesus was the fulfilment of what the sanctuary/temple typified, John 2:19-21, Heb 9:1-28, 10:1-18
- Jesus represented the foundation of the temple as well, 1 Peter 2:4-8 (Compare Isa 28:16, Ps 118:22)
- Jesus’ body was represented by the curtain in the temple, Heb 10:20.
- Jesus was the bread of life, John 6:35, 41, 48 (compare Ex 25:23-30, Lev 24:8).
- Jesus was the light of life, John 8:12, 9:5 (compare the lampstand Ex 25:31-39, Lev 24:3, 4, Isa 53:11, Ps 56:13, etc)
- Jesus provides the water of life, John 4:13, 14 (Compare the laver Ex 30:17-21. See also 1 Cor 6:11)
- Jesus is the promised seed of the woman Gal 3:16 (compare Gen 3:15, and the Abrahamic Covenant)
- Jesus was the Passover Lamb and thus the promised Messiah, John 1:29, 1 Cor 5:7, 1 Peter 1:19 (compare Ex 12:1-14).
- Jesus is the High Priest of the New Covenant in fulfilment of the Levitical covenant, Heb 4:14-16, 5:10, 7:23-28, because He was “pure, blameless, set apart” exactly as the Levites were. See also Heb 9:15, 12:24.
- Jesus provided the blood of the new covenant of which the communion ceremony was to be a memorial, Matt 26:28, Mark 14:24, Luke 22:20, 1 Cor 11:25, Heb 13:20, 1 Peter 1:19 (compare Ex 24:5, 8).
There were several annual "Sabbaths" or festivals which also pointed toward the sacrifice, atonement and final salvation of Jesus. See Lev 23.
Passover - Jesus is our Passover lamb, John 1:29, 1 Cor 5:7, 1 Peter 1:19
Unleavened Bread - this represented sin the need to rid it from our lived following Jesus' sacrifice, 1 Cor 5:6, 8, Gal 5:9, Matt 16:6, etc see also Ex 12;19, 13:7, Deut 16:3.
Pentecost - represented the coming of the Holy Spirit - see acts 1 & 2
The remaining festivals are less explicit but here is a possible interpretation:
Trumpets - possibly alluding to the "last trumpet" at the second coming, Matt 24:31, 1 Thess 4:16
Atonement - possibly alluding to Heb 9:28 - so Christ was sacrificed once to take away the sins of many; and he will appear a second time, not to bear sin, but to bring salvation to those who are waiting for him.
Tabernacles - may be allusion to the heavenly homes of rest Jesus discussed in John 14:1-3.
In Col 2, V16 & 17 cannot be divorced from V14 & 15.
having canceled the debt ascribed to us in the decrees that stood
against us. He took it away, nailing it to the cross! And having
disarmed the powers and authorities, He made a public spectacle of
them, triumphing over them by the cross. Therefore let no one judge
you by what you eat or drink, or with regard to a feast, a New Moon,
or a Sabbath. These are a shadow of the things to come, but the body
that casts it belongs to Christ.
The debt of sin is what was nailed to the cross. However, the Judaizers believed this debt of sin had to be paid by works of the ceremonial law 9or some other law). Jesus paid the debt and the ceremonial system was fulfilled in Christ as listed above.
Ellicott sums up this way:
(14) Blotting out the handwriting—i.e., cancelling the bond which
stood against us in its ordinances. The “handwriting” is the bond,
exacting payment or penalty in default. (Comp. Philemon 1:19, “I Paul
have written it with mine own hand; I will repay it.”) What this bond
is we see by Ephesians 2:15, which speaks of “the law of commandments
in ordinances,” there called “the enmity slain by the cross.” On the
meaning of “ordinances” see Note on that passage. The metaphor,
however, here is different, and especially notable as the first
anticipation of those many metaphors of later theology, from
Tertullian downwards, in which the idea of a debt to God, paid for us
by the blood of Christ, as “a satisfaction,” is brought out. The Law
is a bond, “Do this and thou shalt live.” “The soul that sinneth it
shall die.” On failure to do our part it “stands against us.” But God
for Christ’s sake forgives our transgressions and cancels the bond. It
is a striking metaphor, full of graphic expressiveness; it is
misleading only when (as in some later theologies) we hold it to be
not only the truth, but the whole truth, forgetting that legal and
forensic metaphors can but imperfectly represent inner spiritual
realities. And took it.—Properly, and He (Christ) hath taken it away.
The change of tense is significant. The act of atonement is over; its
Nailing it to his cross.—At this point the idea of atonement comes in.
Hitherto we have heard simply of free forgiveness and love of God. Now
the bond is viewed, not as cancelled by a simple act of divine mercy,
but as absolutely destroyed by Christ, by “nailing it to His cross.”