The Bible’s main purpose is to reveal the plan of redemption and salvation for mankind. All Scripture should be studied in this light. Even when the judgment of God is mentioned, it is with the purpose of bringing deliverance to mankind. One of the Bible’s purposes is that of warning man, individually or corporately, to avoid the consequences of judgment — God’s wrath. If he so chooses, he can escape Hell and go to Heaven.

When studied in the light of God’s purpose to redeem man through Christ’s death, burial, and resurrection, nothing in the Bible can put us into the bondage of legalism (the keeping of laws in an effort to please God). Law is not the theme of the Bible, but redemption through the grace of God.

People are brought into the bondage of legalism when they stop studying the Word of God with the idea of redemption and salvation in mind. Many people come under bondage, not through reading the Word, but through what someone else has said “the Word says,” quoting only a portion of Scripture or quoting a particular interpretation of that verse.
The law reveals our sins, but God’s grace points us to Jesus and His blood to cover and atone for our sins, if we will only receive Him and be born again.

Many people want to throw out the Old Testament, except as interesting Bible stories and history. However, the Old and the New work together (1 Corinthians 10:11). The Old Testament was not erased; the New was simply built upon it. The redemption plan is told in the Old Testament by “types and shadows.” People who were indirect examples of Jesus and the kinds of things He was to do when He came were used as these types and shadows. Also, literal prophecies that directly speak of Jesus fall into this category (Hebrews 10:1)
For example, the temple in the Old Testament was a dwelling place for the Holy Spirit and was a literal building. Under the new covenant, the spirits of those who are born again become God’s dwelling place, individually and collectively. Therefore the New Testament speaks of the bodies of Christians as “the temples of God” (1 Corinthians 3:16). So the temple that was a building to the Israelites, and later to the Jews, was a shadow, a “picture,” of a time to come when man himself could become God’s “house” or “temple.”
Another example is the word virgin in New Testament typology, which means the holy and pure Bride of Christ (born again believers, or the Body of Christ), who has not had intercourse with the world. To those who are not Christians, things like this will not make sense. That is why Paul wrote that the natural mind cannot understand spiritual things (1 Corinthians 2:14).
The redemption plan is told in the New Testament through the reports of Jesus’ birth, life, ministry, death, and resurrection (Hebrews 9:15). Therefore, the Bible’s main purpose is to reveal the plan of redemption and salvation for man, which also is the theme of the entire Bible (Luke 24:27,44). The Old Testament was the written preparation for His coming (Isaiah 40:3). The gospels portray the manifestation of His coming (John 1:29). The Acts of the Apostles is the propagation of His purpose (Acts 1:8). And the epistles, the letters by several of the apostles to various early churches, presented the knowledge, or explanation, of the mystery of Christ and the hope of glory to Gentiles, those formerly alienated from God.
The Revelation of Jesus to the Apostle John tells us of the consummation of God’s plan, of its successful conclusion in victory, just as Genesis tells us of the beginning being marred by sin. Each part of the Bible needs the others to be complete. Therefore, the Old Testament was the preparation for the Lord’s coming; the gospels were the manifestation of the Lord’s coming; Acts was the propagation of the Lord’s Gospel; the epistles were the explanation of the Lord’s Gospel, and Revelation tells of the consummation of the Lord’s Gospel. “Paradise lost” in Genesis becomes “paradise regained” in the Book of Revelation.

(This material was taken from the workbook, “Prove All Things”) by Betty Miller