Hi Golden Maven, according to Peter, a "Christian" is someone who glorifies God, and suffers because of his or her testimony. And according to Paul, a "Christian" is someone who lives a life committed to Christ, just like Paul. So the first point from these two mentions of Christians in the Bible, is a "Christian" would be someone, who if on trial for being a follower of Christ, where there would be ample evidence for a conviction.
But the gospel of Christ tells us that to be "in Christ" is more than simply striving to be like Christ. It is believing "from the heart" and being fully committed, "love God with all your heart." Scripture teaches that if we believe in Him, even in His name, i.e. we believe in what scripture tells us about Christ, that God, who knows our hearts, and knows who are believers, will credit our faith as righteousness, and spiritually place us "in Christ" where we undergo the circumcision of Christ - our body of sin is removed - and we arise in Christ a new creature, born again from above, a "child of God" and thus one who will inherit eternal life. Also, a born again "Christian" will never fall away, because God protects our faith and seals us in Christ with the Holy Spirit.
