Somebody wrote a book on this topic once (hint: C. S. Lewis). But I am not going to attempt to discuss the ‘ins-and-outs’ of the “moral argument for the existence of God;” instead I am going to provide a bit of an sketch on why I think of myself as a ‘Mere Christian’.
In Acts 11:26 it says: “. . . and the disciples were first called Christians in Antioch.” This is the “label,” if any, that I want to wear. It is a name that literally means — Christ ‘in’ — and thus is a moniker that any person who has placed their trust in the Jesus of the bible can claim proudly. Of course, today, ‘Christian’ has many sub-sets underneath it as an general categorization; so that instead of using that “label” we identify ourselves as: Calvinists, Arminians, Neo-Orthodox, Paleo-Orthodox, Biblicists, Evangelical, Fundamentalist, Non-Denominational, Covenant, Baptist, Lutheran, ad infinitum. Certainly these labels, beyond just claiming “Mere Christian,” can be helpful in understanding what theological quirks and idiosyncrasies a particular person believes best represents what it means to be a ‘Mere Christian’ — so I am not really trying to denigrate usage of such ‘markers’. Instead all that I am trying to underscore here, is that if these ‘markers’ become an end in themselves — if we believe that only our particular brand of theology is “Orthodox” and what it means to be a ‘Mere Christian’; then I think we have another thing coming, at the coming of the LORD!
To be a ‘Mere Christian’ simply means that you have followed Jesus’ pronouncement when He asserted:
Truly, truly, I say to you, he who hears My word, and believes Him who sent Me, has eternal life, and does not come into judgment, but has passed out of death into life. ~John 5:24
This is all it takes to be called a ‘Christian’, just like the disciples were first called in Antioch! You might believe that narrowing it down by attaching a certain other label (like the ones I have listed above) to ‘Christian’ is necessary to truly be able to wear this label . . . but I would humbly submit that you are wrong. There is a minimum to what it takes to be a ‘Mere Christian’, and Jesus succinctly summarizes that for us in the passage provided by John the Evangelist.
I find it refreshing to realize that I am simply a ‘Mere Christian’, based upon the simple and Free Grace offered to us by and in Christ; I hope you do too!