In the Old Testament, the nation of Israel was God’s chosen instrument for witnessing about God’s saving grace. It was in this sense that Israel became the “chosen nation” (Ex 19:5). Specifically:
- Israel was to be a kingdom of priests to teach all nations (Ex 19:5, 6, Isa 61:6).
- Israel was to be a light to the world (Isa 42:6, 49:6, 60:3).
- Israel was to be a blessing to all nations via both their spiritual example and teaching, and the promised Messiah (Gen 12:2-3; 18:18; 22:18, Ps 67:1-2, Isa 2:2-4, 55:5, 61:9-11, 66:19-20, Jer 3:17).
Note that while Israel was chosen as the instrument to tell and show the world of God’s saving grace, salvation was always available to all people. Indeed, the Old Testament contains many examples of foreigners becoming part of Israel, indicating that the Israelite Covenant was open to all and was never exclusive. For example:
- Abraham’s own household must have consisted of perhaps 2000 people just to be able to raise an army of 318 men to liberate Lot, Gen 14:14. Indeed, Abraham’s chief servant (from Damascus) was clearly a believer and very devout as shown in Gen 24.
- When Jacob entered Egypt, his family numbered 75 people (Acts 7:14, Ex 1:5). Some of these were not direct descendants of Abraham such as the wives of the 12 patriarchs, notably Joseph’s own wife. 215 years and four generations later at the exodus, Israel’s army had over 600,000 men (excluding women and children) suggesting a total population of several million people, requiring many additions. This included a significant mixed multitude (Ex 12:38) showing that Israel obviously consisted of many non-biological Jews had joined.
- Moses married a Midianite (Ex 2:16-21).
- Caleb, who represented and led the tribe of Judah was a Kennizite (Num 32:12).
- Rahab was a Canaanite (Josh 2:1, 2, Matt 1:5)
- Ruth was Moabite (Ruth 1:4 16, 17, Matt 1:5) – these last two make King David descended from foreigners (Ruth 4:13-16).
- Uriah was a Hittite (2 Sam 11:3)
- King David’s elite personal regiment was Gittite, Philistines (1 Chron 18:17)
- The Rechabites were Kenites (Jer 35:1-19)
- Many other foreigners lived in Israel (1 Chron 22:2, 17, 2 Chron 30:25)
- In Esther’s time “many of the people of the land became Jews” (Esther 8:17, 9:27)
- Even in NT times, many Jewish synagogues were attended by godly gentiles converted to Judaism (Acts 13:16, 26, 16:14, 17:17)
- Many Jewish proselytes came to worship in Jerusalem (John 20:20, Acts 2:9-11)
- Jesus quotes Isa 56:7, “My house shall be a house of prayer for all nations”, Mark 11:17.
- Further, biological Israelites could opt out of the covenant and be cut-off (Ex 30:33, 38, 31:14, Lev 7:20, 21, 25, 27).
Thus, it is abundantly clear that membership of Israel was always open to all and voluntary. The same is true under the New Covenant, Matt 26:28, Mark 14:24, Luke 22:20, 1 Cor 11:25, 2 Cor 3:6, Heb 8:6-13, 9:15, 10:16, 29, 12:24, (Jer 31:31, 33).
The Question: "Could foreigners serve in the Temple specifically?"
The Answer: No. Only the Tribe of Levi (a Cohen) can serve in the temple as Priests. This is the one bloodline that cannot own property, an inheritance, and receives a regular holy day tithing from all the nations. No foreigners or other tribes are allowed to be mixed with this one bloodline and serve in that same generation. There are also other guidelines that are required to be worthy. This is one of the highest and most guarded positions.
The Melchizodek "Priest-King" Priesthood is the main point here, not people's feelings. Gen 14:18-20, Psalms 110, Hebrews 5-7
The Principles of the Priesthood were always in Moses and Aaron's bloodline and re-established at Mt Sinai with the writing of the Torah on the Sapphire Tablets in God's own hand. Then after Moses came down and saw people worshipping the golden calf and broke them, the Stone Tablets God made him remake by hand to learn again. Leviticus 8-10, Exodus 19:22-24, Exodus 28-29.