I know the theological answer to the question begins with what Paul told his prison guard in Philippi: “Believe in the Lord Jesus, and you will be saved.” (Acts 16:31) He adds to that, in Romans 10:9, when he writes, “For if you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved.”
But where do we go from there? That’s a dangerous question. Wars have been fought over that question. (I think those folks missed that passage in John 17:21 where Jesus prayed: “My prayer for all of them is that they will be one, just as you and I are one, Father– that just as you are in me and I am in you, so they will be in us, and the world will believe you sent me.”) There are untold numbers of confessions of faith, commentaries and theological treatise that weigh in on the subject. New denominations have been formed because of different answers to this question.
To be sure, this is an important question. There are many New Testament passages that warn against heresy and urge us to guard the truth at all costs. It is interesting to note that the majority of those passages stood as rebukes to those who were trying to re-introduce religion to the church of the day and, in some cases, profit from the naivety of gullible and immature believers.
So what is the bottom line? Certainly the words of Jesus should have some bearing on the discussion – “Your love for one another will prove to the world that you are my disciples.” (John 13:35) I know there are some who will over simplify this concept building their whole philosophy on a distorted definition of love (i.e., emotion, so-called tolerance, etc.), however, it should be noted that real love is more than an emotion; it is a commitment to what is best for the individual it is directed towards. It is clear, however, that Jesus’ intention is that we live our lives as a genuine expression of his love to the world.