What is the relationship of gentile Christians to the nation of Israel, the land of Israel, and the scriptures of Israel (i.e., what we know as the Old Testament)?
The short answer is that gentile Christians are actually counted as Jews, having been grafted into Israel by their salvation. (Rom. 11: 17-24) The entirety of Romans 11 is a crucial passage for understanding this relationship.
Scripture is very clear that God chose to put His grace on Israel, giving them His presence and His Word. His full intention in this was that through the seed of Abraham, all the nations of the world would be blessed. (Gen. 12: 1- 3; 18: 17-19; 22: 15-18)
This blessing occurs in many ways.
1. God was introduced to the world through His relationship with Israel. He was revealed to them and through them to be fundamentally different than the "gods" that other nations worshipped. Foreigners came to fear the power of Yahweh and also wanted to be part of His provision and protection. (Is. 61: 1-9; 62: 1-12)
2. The Scriptures, which were entrusted to Israel, were not just for their benefit, but also for the benefit of any person who wanted to be joined to them. (Rom.3: 1-2) Throughout the Old Testament, God made allowance for foreigners to be counted among the people of Israel.
It is important to note that whenever the New Testament makes a reference to the scriptures, it is referring to the Old Testament. (e.g., 2 Tim. 3: 16)
3. Ultimately, the Messiah would be born of the tribe of Judah. Jesus is the fulfillment - the end goal - of all that God began when He first called Abraham to be His own.
4. God revealed through Abraham the conditions through which people would be saved and brought into a relationship with Him. That is, that salvation has always been and will always be the result of faith, rather than of good works. (Gen. 15: 1- 6; Rom. 4: 16-25). This was true in the Old Testament as well as the New Testament. Nothing we do will accomplish our salvation - not good behavior or the circumcision of our flesh or going to church. These are things that result from our salvation but they do not grant salvation. (Rom. 3: 28-30; 4: 4-13).
Ultimately then, Jewishness or citizenship in Israel, is not accomplished through genealogy or culture or tradition. Rather it is defined by the condition of the heart. (John 8: 37-42; Col. 2: 11-12; Rom. 2: 26-29). This is why we have passages such as Eph. 2: 11-19
"Therefore, remember that formerly you who are Gentiles by birth and called "uncircumcised" by those who call themselves "the circumcision" (that done in the body by the hands of men)-- remember that at that time you were separate from Christ, excluded from citizenship in Israel and foreigners to the covenants of the promise, without hope and without God in the world. But now in Christ Jesus you who once were far away have been brought near through the blood of Christ. For he himself is our peace, who has made the two one and has destroyed the barrier, the dividing wall of hostility, by abolishing in his flesh the law with its commandments and regulations. His purpose was to create in himself one new man out of the two, thus making peace, and in this one body to reconcile both of them to God through the cross, by which he put to death their hostility. He came and preached peace to you who were far away and peace to those who were near. For through him we both have access to the Father by one Spirit. Consequently, you are no longer foreigners and aliens, but fellow citizens with God's people and members of God's household …"
5. Being grafted into the people of Israel through our adoption in Jesus makes gentile believers joint heirs to the physical land of Israel and to all of the promises and charges given to them as a nation (e.g., Ezek. 47: 21-23; Gen. 12: 1-3).
6. It also makes them joint keepers/guardians of the Word of God entrusted to Israel.
Benefits of understanding the Hebraic roots of Christian faith
By viewing Christianity as the fulfillment of Judaism rather than its replacement, we reap several benefits.
1. It helps us to better understand the meaning of scripture. The Bible was not originally written in English but in Hebrew, Greek and Aramaic. The only way to really understand scripture is to ask what the phrases would have meant to the people to which they were originally spoken. This takes into account the culture in which it was spoken/written as well as the customs of that day.
All language is a reflection of that language's culture. When you translate a Hebrew word into another language, you lose subtle shadings that are dependent on Hebrew culture and history. For example, the Hebrew word torah means instruction. It implies an honor and privilege given to us, a responsibility that we undertake as part of the covenant we made with God, a good deed that we are eager to perform because it please the God who saved us and because we recognize that it is given for our own good. When it is translated into English, torah is usually rendered as the word commandment or law. "Commandment" has a much different implication - a law or order imposed upon us by a stern and punishing God.
2. It help us to see the continuity of Scripture. We have mistakenly believed that the Old and New Testaments were two separate entities, two separate covenants, two disconnected stories. But the truth of scripture is that it is a single story which spans the Old and New Testaments. It is the story of the birth, death, and redemption (resurrection) of the children of God, the sons and daughters of Adam. This is the story of God's desire to have children for Himself and a bride for His son. It is about the lengths He has gone to in order to accomplish those things. Ultimately, the Bible tells the story of God's heart poured out on us, the objects of His great affection.
By way of example ...
As an example of the continuity of scripture, in Lev. 23 God instituted what He called the feasts or festivals of the Lord (notice that these were not called the festivals of Israel, but rather festivals of the Lord). These seven events were prophetic rehearsals of the birth, death, resurrection and second coming of Jesus. They were designed to point the way to Messiah, as their fulfillment would be found in Him. Consequently, many of Jesus' statements which are recorded in the New Testament are references to elements of the festivals (something we cannot understand if we fail to view Jesus in the context of His Jewish culture and faith). For example, Jesus' statement in John 7: 37-38 is a reference to a symbol used in the Feast of Tabernacles. Therefore, some of its significance is lost if we don't understand that Feast.
All people who belong to the Lord were instructed to participate in these festivals until the end of the Age (that is, until the second coming of Christ).
In Lev. 23: 2, the word for feast is the Hebrew word mo'ed, which means "an appointment, a fixed time or season, a cycle or year, an assembly, an appointed time, a set time or exact time. God is saying here that He has ordained specific times (or exact time or an appointed time) when He will meet with humanity to fulfill certain events in the redemption. E.g., Jesus came to earth at the exact time ordained by God (Gal 4:2,4), and God has an exact time or set appointment when, in the future, He will judge the world (Acts 17:31).
Mo'ed is also translated as the tent of meeting that was to be part of the tabernacle of Moses. The tent of meeting contained a table on which was the bread of the Presence and a lampstand that burned oil continually before God. (The book of Revelation uses lampstand to represent the church). The ark of the Covenant was in an area of the tent of meeting called the Most Holy Place. (Exod. 25: 8-22) Here, God would meet intimately with Moses at the mercy seat. It was also the place that contained the word/instruction of God, the staff of authority, and the manna/provision.
In the appointed time (during the festivals), in the tent of meeting (which now includes the human heart and not just a physical structure), we come face to face with the presence of God. We also receive the word/instruction of God, the staff of authority (which allows us to minister in His name), and the manna (provision of God for our lives).
Eddie Chumney has written a very useful book about the relationship of the seven festivals to Jesus (and therefore to Christianity). Below is an excerpt from his book, The Seven Festivals of the Messiah. I encourage you to visit his website. There, you may either order the book or download it for free.
Reasons for studying the feasts
Although God gave us the festivals to observe, God never gave the festivals so we would obtain salvation from Him by observing them because salvation only comes by faith. However, God did give the festivals for the purpose of teaching and instructing His people concerning His plan of redemption and our personal relationship to Him.
The Bible provides several powerful reasons for studying and understanding the seven festivals of the Messiah:
1. The feasts are in the Bible, and all the Bible is inspired by God (2 Tim. 3:16-17).
2. The feasts are a shadow of things to come that teach us about the Messiah (Col. 2:16-17; Heb. 10:1).
3. The feasts are prophetic types and examples foreshadowing significant events in God's plan of redemption (1 Cor. 10:1-6,11; Rom. 15:4).
4. The feasts, as part of the Torah (which means "instruction"), are as a schoolmaster or tutor that leads us to the Messiah (Gal. 3:24).
5. The feasts will point to the Messiah and God's plan for the world through the Messiah (Ps. 40:6-8; Heb. 10:7).
6. The feasts set forth the pattern of heavenly things on earth(Heb. 8:1-2,5; 9:8-9,23; Exod.25:8-9,40; 26:30; Num.8:4; Ezek.43:1-6,10-12).
7. God gives the natural to explain the spiritual (1 Cor. 15:46-47; 2:9-13; 2 Cor.4:18).