I think that of all the people who never read the Bible or know much about the Bible, the one thing they are most likely to know about the Bible is some misconception of 666. Undoubtedly, their misconception is founded upon their attending one of the creations of the equally ignorant Hollywood productions like the Omen series. Did you ever wonder how we would know the number of the so-called Beast? Would the number be written 666 beneath the hair of his scalp like it was done in the Hollywood production? If so, why does the Bible say we must calculate his number (Revelation 13:18)? In the 1970s I remember that some folks thought Henry Kissinger was the Antichrist, because someone calculated K-I-S-S-I-N-G-E-R and came up with 666!
In the Bible, the Greek word used to show how the number 666 is derived is psephizo (G5585) and means “to use pebbles in enumeration; (generally) to compute.” It is also the word used to decide a matter by casting one’s vote (casting pebbles into an urn). So, how would any of us, today, decide who this Beast is, if we had to identify him by ‘counting’ the number of his name? Would we use his English name? What if he is French, Italian or German etc.? How would we count his name, and in what language would we compute it, because his name would be spelled differently in each language (cp. Jesus)? The Bible does not help us here does it? I think this is a significant factor. How would anyone compute the number of the Beast today? In what language would we understand its calculation? It seems to me that, if we are using the Bible, we would need to use its languages (Greek, Hebrew or possible Aramaic) to calculate the number of the Beast’s name, otherwise everything is arbitrary, and what we could calculate in English would not be so in French or German etc. In other words KISSINGER (et al) is not the name of the Beast.
Gematria is a system of assigning numerical value to a word or phrase, in the belief that words or phrases with identical numerical values bear some relation to each other, or bear some relation to the number itself as it may apply to a person’s age, the calendar year, or the like. This is the system that John uses in Revelation 13:18. The Greek letters chi, xi, and stigma are used to express the number 666. Each letter of the Greek alphabet is given a number. The first 10 letters (alpha to iota) are given the values of 1-10 respectively. Then each following number is expressed by counting by 10s (20 to 90 or from kappa to omicron). The final eight letters of the ancient Greek alphabet or from rho to omega are counted in hundreds from 100 to 800 respectively.
Using this formula one could count the value of a single Greek word or even of phrases in the New Testament. For example, and since we are interested in the number 666 in this study, the Greek word wonders in 2Thessalonians 2:9 has the value of 666, so does merchandise in 2Peter 2:3 (except that its value is 666 x 2). The phrase in the world in 1John 1:9 has the value of 666, as does the value of the phrase merchants of the earth in Revelation 18:3. The phrase: The man of sin, the son of perdition in 2Thessalonians 2:3 is 3996 which at first means nothing to our study until we find that this same number can be expressed as 666 x 6.
One of the most interesting things I discovered in my studies on this subject is that of all the nouns in the New Testament only two in their nominative case (this is the case one finds all nouns in dictionaries and concordances such as Strongs and Thayers) have the value of 666. The two nouns are euporia (G2142 meaning wealth) and paradosis (G3862 meaning tradition). These two nouns have a relation to the right hand (wealth) i.e. what we do; and the forehead (tradition) relating to what we believe. This is pretty significant, don’t you think? Only two Greek nouns of all the nouns used in the New Testament have the value of 666, and, taken together, they correspond to the Mark of the Beast!
So, what does all this mean? What should we think of these things? Well, I believe it is rather obvious that it would be arbitrary, to say the least, if we think we should calculate the number of a man’s name today. In what language would we make our calculations? It seems clear to me that, if we are going to understand what 666 means and to whom it refers, it must refer to someone or something in the past, viz. the 1st century AD.
Early Christians understood the number referred to Nero Caesar. In the Aramaic language (a language of the Bible) his name added up to 666. I also think it is quite significant that Annas, the high priest who had so much to do with Jesus’ crucifixion and the first three persecutions against the church, also has this number engraved upon his life. He was murdered by Jewish rebels at the beginning of the Jewish war with Rome. He died on the 6th day of the 6th month, after having been high priest for 60 years. Looking back in the manner in which we have come to calculate time, he was made high priest in the year 6 AD and was killed in the year 66 AD. Admittedly, this calculation is the result of an error in determining Jesus’ birth, but could this human error be by divine design in order to point to this evil man? Just a thought!
 From Strongs Concordance
 From “The Free Dictionary” http://encyclopedia.thefreedictionary.com/Gematria
 All calculations in this paragraph come from Theomatics by Jerry Lucas and Del Washburn; ISBN 0-8128-6017-9.
 This information in greater detail can be found in the commentary Jamieson, Fausset & Brown at Revelation 13:18.
 Josephus dates Annas’ priesthood to 6 AD (see Antiquities of the Jews 18.1.2 ) and puts his death at the beginning of the Jewish war with Rome in 66 AD (see Wars of the Jews 2.17.9 [441-442]. He sets a more exact date in the previous paragraph (2.17.8 ) when he says the fire was set to the Roman camp on the 6th day of the month of Gorpieus / Elul (6th month). For a more detailed analysis of this, see my comment below which is dated October 29, 2015.