To acknowledge as of good standing, or in communion according to standards of faith and practice; to admit to Christian fellowship.

living with other believers and God in spiritual intimacy.

The spiritual relationship between believers and the Lord, and the gathering together of Christians in the name of Jesus. "If we say that we have fellowship with Him, and walk in darkness, we lie and do not practice the truth. But if we walk in the light as He is in the light, we have fellowship with one another, and the blood of Jesus Christ His Son cleanses us from all sin" (1 John 1:6-7).

A sense of belonging to a community, either within a specific church or within Christianity as a widespread religion. This can also refer to socializing exclusively with other Christians. Some individuals and groups consider such exclusivity to be an important factor in spiritual growth and/or righteousness. Source: http://en.wikipedia.org/wiki/Christianese

(Gr. koinonia) Literally, "communion"; the unity of believers through Christ based on the fellowship of the Father, Son, and Holy Spirit. Christians are united into a special fellowship through their love for one another and common union with Christ (Acts 2:42; 1 John 1:3, 7). See also COMMUNION.