The Biblicist said:
There are Biblical essentials that are required to recognize a person as a Christian, without which, they should not be recognized as such.
Likewise, there are Biblical essentials that are required to recognize a group of professing Christians as a New Testament congregation, without which, they should not be recognized as such.
Can you post a scripture reference where the Bible specifically says that there are essentials that are required to recognize a group of people as a "church" and where there are essentials that are required to call a person a "Christian"?
The only comprehensive list I can find is in I John:
1:7, Walk in the light, as He is in the light
1:9, Confess our sin, which leads to forgiveness and purification or sanctification
2:6, Obedience to Jesus, by walking as Jesus did
2:10, Love your brother
2:15, Do not love the world, but do the will of God
2:23, Acknowledge the Son
3:6, Do not continue in sin
3:10, Do what is right, love your brother
3:11, Love one another
3:16, Lay down our life for our brothers
3:17-18, Love with actions and in truth, with material possessions for those in need
3:23, Believe in the name of his son, Jesus Christ and to love one another
3:24, Obey his commands
4:2, Acknowledge that Jesus Christ has come in the flesh
4:7, Love one another
4:15, acknowledge through the Spirit that Jesus is the Son of God
4:16-19, demonstrate God in us by loving our brother
4:21, Love your brother
5:2, Love God and carry out his commands
5:12, He who has the Son has life
5:18, Do not continue in sin
So, here's what I get from that. The essentials for a Christian are, 1) the acknowledgement of Jesus as the Son of God and savior, 2) Repentance and confession of sin unto forgiveness, 3) Obedience to the command of God, which is primarily to love your brother, and 4) Don't continue in sin after you've confessed and been sanctified.