Christianity must be defined by demonstrable love, actual fellowship: “34 A new commandment I give to you, that you love one another: just as I have loved you, you also are to love one another. 35 By this all people will know that you are my disciples, if you have love for one another.” John 13:34-35.
We easily make too little of this point. Yet, if we consider the matter in light of the Lord’s criteria, we must agree with the good doctor:
The first thing we are told is that they came together constantly—“they continued steadfastly”; “and they, continuing daily with one accord in the temple.” All who believed these things, all who were Christians, were constantly found together. So here is my first proposition. One of the first tests you must apply to yourself, or to anybody else, in order to discover whether or not you are a Christian is to ask the question, Do you want to come together with other Christians? If you do not feel this desire, there is only one explanation: You are not a Christian. Now one would have thought that it would be unnecessary to say a thing like that, but, sadly, this warning is needed.