2 Timothy 2:15 Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth.
As sincere and as well meaning as a person may be, right is still right and wrong is still wrong. Someone may be the kindest, nicest, politest, honest, and generous person you will ever meet and yet they can still be wrong when it comes to their Bible understanding. It would probably not be a stretch to believe that most people that stake claim to being a saved Christian are no more saved than the man on the moon if they cannot with clarity state how a soul is saved during this present dispensation of God's grace. You cannot look at someone and make the determination if a person is indeed a Christian, it is according to what one believes and places their faith in that makes that determination. Many will say they believe in Jesus, but what does that actually mean? As children, we were taught to believe in Santa Claus and the Easter bunny and in so doing, we would receive gifts only later to discover there were no such characters. Our childish beliefs were not based upon knowledge, but upon what we were told to believe. That same scenario is pervasive in churchianity whereby the people are being led by a pastor or a teacher rather than basing their belief system grounded by personal Bible study. This is one type of person that says they are a Christian.
The other type of person that says they are a Christian is one that may have a fair to good deal of Bible acumen and have failed to understand the doctrinal differences between the covenant nation of Israel and the church, the body of Christ which is the new creature. The first type of person is a joy to deal with because they are not tainted by false teaching and are clean slates ready to be presented the gospel of the grace of God with clarity. The second type is most challenging in that they are in need of reteaching but will be hard to convince of their error. They have already accumulated doctrines from all over the Bible and have blended everything from everywhere, here a verse, there a verse, everywhere a verse verse into one belief system which happens to be an egregious error. They read things back into scriptures things that were not revealed until later, failing to see the progression in revelation of the scriptures. This type of sincere person who has been taught or even studied by himself will use terminology from anywhere in the Bible and apply it to themselves such as saying they are "born again" or say things like they will "endure unto the end" to be saved. Terms like repent being dealt around as if it meant to "turn from you sins" or everywhere they see the word "baptize" their mind goes to thinking about a water ceremony. They may refer to themselves as a "priesthood" of believers, or a "flock", a "royal priesthood", "chosen", "sheep", "new testament Christian". These folks will answer the simple question of "how is a soul saved" with statements like " If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness" or they will pull out the big guns on you and quote John 3:16 and then tell you we need to keep the commandments.
In both types of people we should be able to discern their need is one and the same, a clear presentation of the Gospel of the grace of God in that Christ did everything necessary to save our never dying souls. It was Jesus that died for our sins. It was Jesus that was buried. It was Jesus that rose again the third day with victory over death, Hell, and the grave. The only participation that we have in the salvation transaction is that we are the sinners for whom Christ died and if we place our belief, trust, and faith in what Christ did, God counts our faith for righteousness and the Holy Spirit of God baptizes us into the body of Christ, the new creature. It is just that simple!!