The New Testament Church of God began on the Day of Pentecost after the ascension of Jesus Christ to heaven. God poured out His Spirit on the disciples who were assembled together on that day in obedience to Christ's command to remain in Jerusalem (Luke 24:49; Acts 2:1-4; Acts 5:32). Over the next several days, God "added to the church daily those who were being saved" (Acts 2:47).

The word church is used to translate the Greek word ekklesia. At the time of the writing of the New Testament, ekklesia was a common word for civic gatherings, formed from the noun form of the verb kaleo (meaning "to call") and the prefix ek (meaning "out of"). From kaleo also comes klesis ("calling") and kletos ("called").

The compound ek-klesia, then, means a body of people "called out" to assemble together, just as ancient Israel was called out of Egypt to assemble before God as "the church [ekklesia] in the wilderness" (Acts 7:38, King James Version)—or "the congregation in the wilderness" (NKJV). The word ekklesia was used in the Greek Septuagint translation of the Old Testament for many instances of the Hebrew kahal, usually rendered "assembly" or "congregation" in English Bibles.

In the first New Testament occurrence of ekklesia, Jesus during His ministry promised, "I will build My church" (Matthew 16:18) or "I will build my assembly" (Young's Literal Translation). He was referring to establishing a summoned gathering of people sharing a common identity.

The aspect of calling here is vital. The apostle Paul in 1 Corinthians 1:2 referred to "the church [ekklesia, or the called out] of God . . . called [kletos] to be saints [sanctified ones—those set apart]." It is the special calling of God, as well as the presence of the Holy Spirit in the minds of those who heed that call, that identifies the Church of God as a unique assembly of people (Acts 2:38-39; Romans 8:9; Romans 8:28-30; 1 Corinthians 1:9; 1 Corinthians 2:12-13; Ephesians 4:3-6).

In referring to this calling, Jesus said, "No one can come to Me unless the Father who sent Me draws him" (John 6:44) and unless "it has been granted" by the Father (John 6:65). Therefore, no one can become part of the Church on his own, as an act of himself. Rather, God initiates and guides the process by leading a person to repentance and baptism for the remission of sins and giving the gift of the Holy Spirit (Acts 2:38), through which a person becomes a member of the Church.

Since it is the indwelling presence of God's Spirit that identifies and unifies God's people (1 Corinthians 12:12-13), the Church is a spiritual organism. Its members are, figuratively, "living stones . . . being built up a spiritual house" (1 Peter 2:5). God the Father and Jesus Christ live within this "house" of believers through the Holy Spirit (John 14:23; 1 John 3:24).

Likewise, Ephesians 2:19-22 describes the Church as a "holy temple . . . built together for a dwelling place of God in the Spirit." The physical body of each individual member is also called "the temple of the Holy Spirit" (1 Corinthians 6:19).

The imagery of a unified spiritual organism is more directly brought out in the fact that Jesus Christ is referred to as the living Head of the Church, which is described as "the body of Christ" (1 Corinthians 12:27; Ephesians 1:22-23; Ephesians 4:12; Colossians 1:18).

The Bible refers to the entire Body of Christ or an individual congregation by the name most English versions translate as "the church of God," and to more than one congregation as "the churches of God" (plural). In 12 instances in the New Testament, the name of the Church occurs with the distinction "of God" (e.g., Acts 20:28; 1 Corinthians 10:32; 1 Corinthians 11:22; 1 Corinthians 15:9; 1 Timothy 3:5). This is in keeping with Jesus' prayer on the night before His death, "Holy Father, keep through Your name those whom You have given Me" (John 17:11).

Yet because the Church is the Body of Christ and He referred to it as "My church," we also see the description "churches of Christ" (Romans 16:16). Still, "the church of God" is the common name. And we also see place names used to signify particular congregations. For example, we read of "the church of God which is at Corinth" (1 Corinthians 1:2; 2 Corinthians 1:1), "the church in Cenchrea" (Romans 16:1) and "the churches of Galatia" (Galatians 1:2). Again, the reference is to a called-out gathering of people.

From the very outset God determined to call His people of this age: "For whom He foreknew, He also predestined to be conformed to the image of His Son . . . Moreover whom He predestined, these He also called" (Romans 8:29-30).

These are intended to be God's "firstfruits" in the spiritual "harvest" of mankind—an initial gathering of people into God's family prior to bringing the rest of humanity into this relationship following Christ's return (compare Matthew 9:37-38; John 4:35; Romans 8:23; James 1:18).

The faithful patriarchs and prophets of the Old Testament are among these firstfruits in the formation of the Church as God's spiritual temple—it "having been built on the foundation of the apostles [of the New Testament] and prophets [of the Old], Jesus Christ Himself being the chief cornerstone" (Ephesians 2:20).

There are many parallels between the nation of Israel in the Old Testament and the New Testament Church of God. The Israelites were considered firstfruits, but they disobeyed God (Hosea 9:10). Israel was God's "firstborn" (Exodus 4:22). And the New Testament Church is the "general assembly and church of the firstborn" (Hebrews 12:23).

Israel was initially, as mentioned, God's ekklesia (called-out assembly or church) in the wilderness (Acts 7:38). The nation was to be a "special treasure" to God, "a kingdom of priests and a holy nation" (Exodus 19:5-6). And the Church is now to Him "a chosen generation, a royal priesthood, a holy nation, His own special people" (1 Peter 2:9).

Paul in Romans 11 explained that, despite nationwide disobedience, there would always be a faithful remnant of Israel—and that the Israelites who repent, along with gentiles (non-Israelites), could be grafted in to Israel. He told gentile converts to Christianity, "If you are Christ's, then you are Abraham's seed, and heirs according to the promise" (Galatians 3:29).

In Romans 2:25-29 he explained that being reckoned as a Jew is a matter of obedience through a right heart in the Spirit: "He is a Jew who is one inwardly." He also referred to the Church as "the Israel of God" (Galatians 6:16).

Thus the Church is spiritual Israel. And some prophetic references to Israel, Jerusalem and Zion apply to the Church. This is not a replacement theology claiming that all prophecies and promises to Israel are fulfilled in the Church. For clearly there is still a role to play for the physical descendants of Israel. National promises and prophecies still apply to them. Rather, the Church is a forerunner in the covenant relationship God promised to Israel.

The physical nation of Israel broke God's former covenant, the lesson being that a nation blessed with abundance, the best laws and even God's visible presence and intervention would not succeed in sustained obedience to Him. Only through a change of heart would this be possible.

So God said He would "make a new covenant with the house of Israel and the house of Judah" (Jeremiah 31:31; Hebrews 10:16-17)—a covenant in which there would be forgiveness of sins and lawful obedience evermore through God's law being written on the people's hearts (accomplished through the indwelling of the Holy Spirit).

This covenant has been initiated with the Church. It is in fact a marriage covenant (see Jeremiah 31:32). The Church is betrothed to Christ as a bride to a husband and will spiritually marry Christ at the time of His return—this relationship being the spiritual reality upon which human marriage is to be modeled (Ephesians 5:22-33; 2 Corinthians 11:2; Revelation 19:7, 9).

In preparation for that time, God has called us out of the evils of this world (John 17:15-16) and sets us apart by the truth of His Word (John 17:17). Jesus has also directly commissioned His disciples to proclaim the gospel, or good news, of the Kingdom of God to the world as a witness (Mark 16:15; Matthew 24:14). He further told them to make disciples of all nations (Matthew 28:19), feeding Christ's flock (see John 21:17) and, in the footsteps of John the Baptist, "make ready a people prepared for the Lord" (Luke 1:17).

The proclamation of the gospel is to be accompanied by a call to repentance (Mark 1:14). As part of that, Jesus and His disciples set an example of warning about the consequences of sin—including destruction prophesied to come on nations and individuals.

The preaching work of the Church, coupled with the combined testimony of individual lives of Church members, provides a powerful message of hope and illumination to a darkened world (Philippians 2:15; Matthew 5:14-16). Members of God's Church are transformed by the renewing of their minds through the power of God's Holy Spirit (Romans 12:2).

The Church also provides a haven for fellowship (Acts 2:42; 1 John 1:7), encouragement (Hebrews 3:13; Hebrews 10:24) and spiritual nourishment (Ephesians 5:29; Colossians 2:19). God has given spiritual gifts to every member for the edification of the body (Romans 12:3-8; 1 Corinthians 12:4-30; Ephesians 4:7-8; Ephesians 4:11-16). These gifts are to be exercised with love (1 Corinthians 13:1-3). Loving one another establishes members' credibility as disciples of Jesus Christ (John 13:34-35).

As an organized body and spiritual nation, the members of the Church have different roles and responsibilities. Some are placed into positions of leadership, preaching and teaching to help members reach their potential, promote unity and protect against false teachings (see Ephesians 4:11-16). The ministry of Jesus Christ is to exercise its spiritual authority for the service and benefit of God's people. Christ said to let "he who governs [be] as he who serves"—following His own example of selflessly serving and giving (Luke 22:26-27).

Part of the ministry's responsibility, along with proclaiming the gospel, is to baptize and lay hands on new converts for the receiving of the Holy Spirit.

As part of their work, they have also been authorized to, in Jesus' name, cast out demons and lay hands on the sick with anointing oil and pray for healing (Mark 16:17-18; James 5:13-18). Yet, while God has established this authority and practice and often intervenes according to it, He may require further conditions such as faith, repentance, obedience and persistence in prayer.

Even so, there are times when in His infinite wisdom God chooses to not intervene at the time or in the manner prayed for. Still, we trust that "all things work together for good to those who love God, to those who are the called according to His purpose" (Romans 8:28). The personal duty of every Christian is to "seek first the kingdom of God and His righteousness," in which case all other needs will ultimately be taken care of (Matthew 6:33; Matthew 6:25-34).

With the Christian faith having been "once for all delivered to the saints" during the first century (Jude 1:3), Church members were encouraged to hold fast to the teachings and traditions of Jesus Christ and the apostles as found in Scripture (2 Thessalonians 2:15). Yet they were also warned against false teachers proclaiming a different gospel and a different portrayal of Jesus (2 Peter 2:1; Galatians 1:6-9; 2 Corinthians 11:4).

Paul warned that apostasy would arise from within the Church and draw people into error (Acts 20:29-31). And he wrote of a "mystery of lawlessness . . . already at work" (2 Thessalonians 2:7). Historically, the original apostolic Church, which adhered closely to God's law, faded from view as a great false Christianity assumed prominence. Most of what goes by the name of Christianity today is saturated with teachings and practices originating in ancient pagan religion and philosophy. This is a major aspect of what the Bible calls "Mystery, Babylon the Great" (Revelation 17:5).

Yet in spite of persecutions and periods with very small numbers, true Christianity never disappeared. Jesus promised that His Church would never die out (Matthew 16:18) and that He would never leave or forsake us (Hebrews 13:5). He promised to be with His people "even to the end of the age" (Matthew 28:19-20), empowering them to do His work. We believe that we in the United Church of God, an International Association, are carrying on in this same tradition.

When Christ returns to the earth to establish the Kingdom of God over all nations, the called-out ones of His Church will be glorified and made perfect through resurrection and instantaneous change to rule with Him (Revelation 2:26; Revelation 3:21; Revelation 5:10; Daniel 7:22; Daniel 7:26-27), having become teachers and judges over men and even angels (1 Corinthians 6:1-3).