This is a ring-necked duck. Do you see the ring? I bet you don’t.
But now let me tell you the ring around the neck which the duck is named after is chestnut brown. In this picture the ring is partially visible.
Back when the bird was named they did most of their study with the aid of a shotgun. When looking at dead specimens in a lab the ring around the neck was this bird’s most obvious trait.
However when you look at a living example of the species it is nearly impossible to see any brown on it. This means the trait that it is named for is totally useless as a field mark to identify the bird by in the wild. Instead people identify it by the purple sheen of the head, and the slight crest making the head seem pointy. From closer up they recognize it by the distinct black, white and charcoal color pattern on the bill. From further out they recognize it by the white spot on the side between the light grey and the black breast.
All of these things are great field marks and yet the distinctive feature it is named after is not visible until the duck is dead.
The Christian life is like this. The common idea is that anyone gets to call themselves Christian. They determine for themselves what criteria they meet to bear that name. Trying to tell people there is a real eternal definition of the word which must be met is useless because they believe they get to make up their own definitions.
But no matter what happens in this life once we are dead, once we stand before the eternal judge, it will be obvious what we are. We will either be identified by Him as Christians or informed that He never knew us and cast into outer darkness.
That field mark which will show up so brightly in heaven is whether we have Jesus in our hearts. Not a designer Jesus we came up with or that some group redefined historically, but the real Jesus. The Eternal Son of God who came and died on the cross for us.
Romans 10:13 (HCSB) For everyone who calls on the name of the Lord will be saved