Col 2:17... Which are a shadow of things to come ... Heb 10: 1 For the law having a shadow of good things to come, and not the very image of the things ... Romans 15:4 For whatsoever things were written aforetime were written for our learning, that we through patience and comfort of the scriptures might have hope.
As we know, "All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, throughly furnished unto all good works." (2 Tim. 3:16-17). Namely, this section of Scripture teaches us that all Scripture (66 books of the Old and New Testaments) is inspired by the Holy Spirit, and is useful to us in four different ways: for DOCTRINE, REPROOF, CORRECTION, and INSTRUCTION, of course in the righteousness of JESUS CHRIST (by faith of Jesus Christ; Rom 3:22, Gal 2:16), which is now OURS by faith in Him (Romans 4:5, 1 Cor. 1:30, 2 Cor. 5:21).
Considering the above texts, we can easily conclude that throughout the history of the human race, God has taken care of and addressed various groups of people in different ways. For example, the most famous groups of people the Lord deals with are the Israelites under the covenant of Moses - most of the books of the Old Testament and part of the books of the New Testament - and the Church of God which is under the New Covenant (Testament) — most of the books of the New Testament (Dividing line was and is the cross of Calvary; Heb 9:15-17). What we can notice is that these are different groups of people with whom God deals in different ways. Accordingly, we can conclude that the whole of Scripture was not written directly to us (the Church), but that some parts of Scripture were addressed to other (different) groups of people (to Israel, as we stated above in the example). However, as our texts above teach us, we find shadows of reality throughout Scripture (typologies), spiritual lessons and principles (of course, in the context of the Church - because we read the Scriptures from our own perspective) from which we can draw spiritual lessons. Let's go through the verses in order:
Col 2:17 & Heb 10: 1
These verses teach us that the law of Moses had a shadow of future goods, but not the ultimate reality. The verse in Colossians is telling us "that the Body is of Christ", which means, if we combine the verses, that the New Testament is the ultimate reality because Christ fulfilled the Law and the Prophets, and he is the one all of the Scripture is pointing to, and the Church of God, which is his Body and his fullness is a part of that reality as we read in Ephesians: "Which he wrought in Christ, when he raised him from the dead, and set him at his own right hand in the heavenly places, far above all principality, and power, and might, and dominion, and every name that is named, not only in this world, but also in that which is to come: And hath put all things under his feet, and gave him to be the head over all things to the church, Which is his body, the fulness of him that filleth all in all. (Eph 1:20-23)
Romans 15: 4
This verse covers the entire Old Testament even more precisely. It talks about everything that was once written. In context, all before the proclamation, that is, enforcing of the New Testament (Covenant). I should also add, that the New Covenat has two applications; on the Heavenly nation (Church of God) and on the Earthly nation (Israel). Second application still has not came to pass, as Israel is put aside because the Lord is now dealing with gentile nations and grafting them into the Olive tree as wild branches (See Romans 9-11 for more info). Since the Church of God is a spiritual heavenly nation, she in not obligated to follow the Mosaic Covenant (Instead, she is following the Law of Spirit), while Israel will follow Mosaic law implanted in new hearts as she will be BORN AGAIN as a NATION on the Great Day of ATONEMENT, aka, second coming of Christ (Col 2:17 kicks in - the Wife of Christ who shares his bliss will come with him - thus pre - tribulation rapture) to rule and reign from the Throne of David as the KING of KINGS and the LORD of LORDS (Luk 1:32-33), together with his Wife (the Church) and the groups of Saints of all the ages.
Therefore, because past things are actually typologies, images and shadows of reality that are now revealed to us (the Church), and it is about different groups of people in different times (periods), and under another Covenants, in that sense all Scripture is useful to us for DOCTRINE, REPROOF, CORRECTION, and INSTRUCTION in righteousness. The apostle Paul, in his first epistle to the Corinthians, teaches the Church this principle, namely, he speaks to them, in the context of God's inspiration of Scripture: "... comparing the spiritual with the spiritual." (1 Cor. 2:13).
As we are going through the Word of God with these notions in our mind, we will be pleased to explore God's Word and, as our beloved brother Paul says, "that we through patience and comfort of the Scriptures might have hope" as we learn and understand that the Scriptures are always pointing us towards Christ (Rom. 15: 4), and that we can comprehend great depth of the Word of GOD: "That Christ may dwell in your hearts by faith; that ye, being rooted and grounded in love, may be able to comprehend with all saints what is the breadth, and length, and depth, and height; And to know the love of Christ, which passeth knowledge, that ye might be filled with all the fulness of God (Ephesians 3:17-19.) It is wonderful to see Christ in every corner of Scripture, and to see that the whole Scriptures are about his atoning work and him alone!
We see that all Scripture is spiritual (inspired by God), and by the command: "Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth." (2 Tim. 2:15) in all wisdom:" Let the word of Christ dwell in you richly in all wisdom." (Col 3:16a), considering our opening texts (Col. 2:17, Rom. 15: 4 & Heb. 10: 1), we clearly see that the whole Scripture is FOR us, but the whole Scripture is not addressed TO us (for example, it is useful to be well acquainted with the sacrificial system of the law of Moses, but it is by no means applicable to the Church. In the same manner, the Lord wants us to know all about Noah's ark, but building it would not be useful for "salvation" to us Christians). That is the meaning of rightly dividing in all wisdom, as we understand that, although all of the Scripture is the Word of God, not all of it is addressed directly to us as a commandment to obey. We simply draw from it an example, an image, a principle and a lesson as the apostle Paul is teaching us.