Following Pentecost and the birth of the Church (Acts 2:1), there were four categories of people: Jews, Samaritans, Gentiles, and Christians. This can be seen by observing what Jesus told His disciples just prior to His Ascension in Acts 1:8. He said, "But ye shall receive power, after that the Holy Ghost is come upon you: and ye (the Church) shall be witnesses unto Me both in Jerusalem, and in all Judaea (the Jews), and in Samaria (the Samaritans), and unto the uttermost part of the earth" (the Gentiles). The Church eventually included believers who formerly had been Jews (Acts 2:5), Samaritans (Acts 8:14), and Gentiles (Acts 10:45).
Denominations are another way to recognize divisions within the Church, but perhaps the most important division is that of spiritual maturity. The Bible describes two kinds of Christians: Babes, or immature Christians (Rom. 2:20; 1 Cor. 3:1-4; Heb. 5:13; 1 Pet. 2:2). Notice in the 1 Corinthians 3:1 that baby Christians are equated with "carnal" believers. The word "carnal" is translated from the Greek σαρκικός (sarkikos), meaning "living according to the flesh," as opposed to the mature or the spiritual believer, from the Greek πνευματικός (pneumatikos), meaning to live according to the leading of the Holy Spirit within.
In the Parable of the Sower (Mt. 13:1-23), I believe Jesus taught about the the difference between the carnal Christian, and the Spirit-led believer. The immature or carnal believer lives a defeated Christian life because of fear (13:5-6 / 20-21), or because of temptation (13:7 / 22). The mature, victorious, or Spirit-led believer is a soul-winner, both by his example and by his words (13:8 / 23).
You be the judge; if you are saved, what kind of born again believer are you?