In fact, the "label" Christian was not even applied to members of the Body of Christ until Acts 11:26. Does that mean the genuine members of the Church were not saved prior to Barnabas joining up with the Apostle Paul? Certainly not. The Church began on the Day of Pentecost, and continued to grow long before the term was applied to its members. So what were the members of the early Church called? They were simply called "believers" (Acts 2:44; 4:4, 32; 5:14; 8:12, 13, 37; 9:42; 10:43, 45).
So what is it that made those believers, from Pentecost until the term "Christian" came into being, saved? It is what they believed! Peter's first sermon on the Day of Pentecost included the following statement: "Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost" (Acts 2:38). In Luke's Gospel, Jesus told His disciples that "repentance and remission of sins should be preached in his name among all nations, beginning at Jerusalem" (Lk. 24:47). "Remission" refers to the finished work Christ did for sinners. In other words, it refers to the Gospel (1 Cor. 15:1-4). All Christians know that, so why are not all Christians saved? The answer is, not all who profess to be Christians have actually repented (turned to God from their old way of life). Hear me out.
Jesus said "Except a man be born of water (physical or natural birth) and of the Spirit (made alive spiritually), he cannot enter into the kingdom of God" (Jn. 3:5). He told His disciples that when the Spirit comes, He will convict the (lost) world of "sin" (theirs), "and of righteousness" (Christ's), "and of judgment" (all who reject Christ's gift of righteousness will be judged - Jn. 3:18; 2 Cor. 5:21). Repentance occurs when a person recognizes his lost condition, when he realizes his only hope of avoiding God's righteous judgment is by trust in Christ, and he turns from being his own god, to allowing the One True God to rule and reign in his heart.
There are lots of Christians, but only born again believers are saved!