Why does your count say 3 John has 15 verses when my Bible says it has 14?
Believe it or not, that is not a mistake, miscount or typo. Also, I receive e-mails, cards and letters pretty regularly from people wanting to help make me aware of this discrepancy. Still, my verse count remains at 15 (with one small adjustment), and here's why...
If you have ever cross-examined various Bible translations I'm sure you will have noticed that the number of verses in 3 John varies, while the same material is still included in the text; in other words, some translations include the closing greeting as one verse (yielding 14), while others split it into two verses (yielding 15 total). Your final total entirely depends on the person counting and the source material (i.e. translations) he or she is using to obtain their count.
Here is a list of English Bible translations in which 3 John has 14 verses: King James Version, New International Version, American Standard Version, Darby's English Translation, New Testament in Modern Speech, 21st Century King James, Wycliffe Bible, New Life Bible, and New International Reader's Version.
The New King James Version and Holman Christian Standard Version only number the verses to 14, but the copies I have seen make a prominent break in verse 14 at the point where 15 begins in other translations... Kind of a "middle ground", where the translators appear to acknowledge the existence of a 15-verse text tradition without actually changing their numbering from the "longer standing" traditional system. I consider those and similar translations as "14 and 1/2" in their verse count.
Here are some English Bible translations with 15 verses in 3 John: Contemporary English Version, Amplified Bible, New American Standard Bible, English Standard Version, God's Word Translation, International Standard Bible, New Living Translation, New Revised Standard Version, and Young's Literal Translation.
There even exists an English translation with 13 verses in 3 John (!): the Worldwide English Translation.
Incidentally, I also checked some Spanish and Romanian translations (because I have access to them and experience in those languages) and even Greek. Of the Spanish translations I checked, 4 had 15 verses: Nueva Versión Internacional, Biblia de las Américas, Castilian, and the 1960 and 1995 versions of Reina-Valera; and only one had 14 verses, that being the Reina Valera Antigua (an older translation). Of the 4 Romanian versions I checked, 2 older translations had 14 verses and the 2 newer translations had 15 verses in 3 John.
As for the Greek:
1550 Stephanus has 14 verses
1881 Westcott-Hort NT has 14 verses, but notes where verse 15 begins in brackets
1894 Scrivener NT has 14 verses
1993 UBS Nestle-Aland 26th Edition NT has 15 verses
What I notice is that translations relying on older Greek text scholarship (such as the "Textus Receptus") tend to lean towards a 14-verse count for 3 John and translations rooted in TR families tend to maintain that verse count, as well. Also, some translations from newer Scholarship apparently tend to stick to the "traditional" English translation verse numbering system, probably to avoid confusion. However, the bracketed presence of a 15th verse in the 1881 Westcott-Hort Greek leads me to believe that a 15-verse numbering system already existed even then.
It's important to note, however, that the original texts were not divided into chapters and verses, and the traditional numbering system most commonly used today was not introduced until many centuries after they were originally written. In fact, the standard chapter/verse divisions used by Jews do not even match the chapter/verse divisions used by Christians for the Old Testament (but that's kind of off the topic right now). If you'd like some more in-depth information about the history of the traditional verse numbering system, you can check out the following web page: http://www.fuller.edu/ministry/berean/chs_vss.htm
As I noted in my personal notes regarding my verse count, I used the Amplified Bible as my main reference for the primary count, and then compared that tally against several other translations (many of which I listed above) in English, Spanish, Romanian, and Greek. In the end, I decided to maintain my 15-verse count for 3 John because (A) my original source translation plus several other English translations use it, (B) the most recent Greek text scholarship tends to support it (e.g. USB Nestle-Aland 26th Edition NT), PLUS most of the English translations with a 14-verse count are based on older Greek text scholarship, and (C) I personally feel more comfortable including a "high" tally (i.e. more inclusive) rather than a "low" tally (omissive) for my final count.
If, for your purposes, you prefer to maintain a 14-verse count for 3 John, simply drop the total number of verses for the NT and the entire Bible by 1 each.