The word 'fellowship' in the New Testament (as in Acts 2:42) is a translation of the Greek word 'koinonia.' At its root 'koinonia' describes two or more people in close association and often speaks of these people as sharing in something, such as a marriage or business. Christian 'koinonia' exists between everyone who knows God through Jesus Christ (see 1 John 1:3). Everyone united with Christ by faith is also united with everyone else united with Christ. The same Holy Spirit indwells all believers and gives each a common share in the body of Christ, the church. As the apostle Paul put it, 'For by one Spirit we were all baptized into one body...and all have been made to drink into one Spirit' (1 Corinthians 12:13).