Are you there God, It’s me, Dean Winchester Behind The Ledgend

Seals and Witnesses in Revelations

There are two witnesses in the bible that are killed and after many days they are resurrected by God. These witnesses are never buried but are left laying in the streets while people celebrate over their deaths.
http://users.aristotle.net/~bhuie/2witnesses.htm

Here is an excerpt about the two biblical witnesses from the web site.
REVELATION 11:3 "And I will give power to my two witnesses, and they will prophesy one thousand two hundred and sixty days, clothed in sackcloth." 4 These are the two olive trees and the two lampstands standing before the God of the earth. 5 And if anyone wants to harm them, fire proceeds from their mouth and devours their enemies. And if anyone wants to harm them, he must be killed in this manner. 6 These have power to shut heaven, so that no rain falls in the days of their prophecy; and they have power over waters to turn them to blood, and to strike the earth with all plagues, as often as they desire. (NKJV)

The Seals in the bible are Seven not 66 as shown in the show.
http://www.biblewheel.com/topics/SevenSeals.asp

An excerpt from the book of sevens, Revelations is below:
This brief review of the meaning of the Number Seven now brings us to the Capstone Book of the Holy Bible, sealed by God with the Seal of Seven. In perfect harmony with its plain and obvious symbolic meaning taught throughout His Word, God completed the Bible with a climaxing flourish of sevens seen nowhere else in all Scripture.

Indeed, the Last Book is sometimes called the "Book of Sevens" because of its unique emphasis upon that number. The table shows many of its surface level appearances, but there also are subtle patterns of seven running throughout its text, such as the seven blessings given to the saints and sevenfold praise of the Lamb that was slain:

The information used in the show is merely a plot device or maybe a play on words.
Numbers are however, very important in the bible.
http://www.christcenteredmall.com/teachings/symbolism/numbers.htm
The web site above gives information on several numbers used symbolically in the bible

An excerpt from the page:
The simple numbers of 1 through 13 have spiritual significance
Multiples of these numbers, or doubling and tripling, carry basically the same meaning only intensifying the truth. It is important to note that the first use of a number in scripture generally conveys its spiritual meaning throughout the rest of the passage.