From The Opinionated Dictionary Of Religion:
Numerology. noun. Knowledge by numbers.
Most ancient cultures utilized numbers as symbolic representations of ideas, and it is curious that numeric symbols are often similar in world traditions. How to explain this?
One view says numeric symbols arose in Africa with remotest humanity and the peoples of the African exodus took those symbols to all other continents.
Another view might say numerical ideas passed via direct contact from culture to culture thousands of years after early humans came out of Africa.
Or, yet another opinion could say symbolic similarities occurred in different times and places because the inherent logic of a number led people to similar figurative conclusions. The concept 'one' lends itself to a symbolism of unity anywhere, any time.
Which ever way numerology got its start, our understanding of symbolic competency in prehistoric humans--gained through anthropological observation of aboriginal peoples--suggests that prehistoric peoples used numbers to signify ideas even before written numerals existed.
Many numerological flourishes found their way into religions.
ONE is for the unity of God. TWO, for duality and opposition, as in the ditheism of Devil vs. God. THREE is for the synthesis of the contradiction between the one and the two. FOUR is for the seasons and the directions. FIVE is for humanity, for our five senses, our five-fingered hand. SIX is for humanity too, created on the sixth day.
And SEVEN? Seven is perfection: a perfect cycle of a week's days. There are the seven fates of ancient Egypt and seven houses of its underworld, each with seven gates; seven strings on Greek Apollo's lyre, seven pipes of Pan, seven daughters of Atlas becoming the seven stars of the Pleiades; seven jewels of Hindu brahmanas; seven steps of Buddha; seven Israelite trips around the walls of Jericho, seven bindings of Sampson, seven months before Noah's ark landed, and seven days before the ark's dove took flight, seven branches of the menorah; seven doors to Mithra's cave where there were seven altars; seven statements of Jesus from the cross, seven Christian sacraments, seven gifts of the spirit, seven trumpets and seven churches and seven seals in the book of Revelation, seven deadly sins, seven virtues; seven Islamic heavens and hells.
Some religions equate letters with numbers. Therefore a word or a name can have a numerically symbolic meaning. Gemetria in Judaism and Ilm-ul-huruf in Islam entail the study of hidden meanings discerned through the numerical equivalence of letters. So, the Hebrew letters in king David's name add up to seven, a perfect number. Arabic letters in the names Adam and Eve add up to the sum of the letters in the name Allah. And so on.
There are those who incline to literalness and really believe there are metaphysical and occult implications in numbers.
There are those who tend toward metaphor and do not accept numerology literally but appreciate that most sacred writers employed numbers as part of their metaphorical repertoire. These people need not believe in the efficacy of the signs of zodiac, the historicity of the tribes of Israel, the genuineness of the disciples of Mithra, or the reality of the disciples of Jesus, but they understand the significance of the number TWELVE for each.
And finally there are those who possess the kind of psyche that embraces both literal and metaphorical meaning at once. It might be said that these people, in sum, carry the two.
For them, there were literally, historically, actually, seven trips around the pre-fallen walls of Jericho. And that real event may metaphorically signify any number of spiritual lessons, as, say, seven attempts at defeating a personal hermeneutical vice.