The start of the three and a half years tribulation under the beasts of Revelation chapter 13 will occur once the abomination that makes desolate is SET UP (Lk.21:20, Dan.11:31, Dan.12:11).
The abomination that makes desolate is a decree that will be enacted that will cause that as many as will not worship the image of the beast should be killed (Matt 24:9, Re.13:15, Re.11:7, Re.12:17, Re.17:6, Dan.8:24, Dan.12:;6-7, Dan.7:21, Dan.7:25, Re.13:7, Re.16:6).
The decree will be ENACTED 1290 days (Dan.12:11) prior to the sounding of the Seventh, and final, Trumpet (1 Thess.4:16-17). Thirty days after the law is ENACTED, 1260 days, or three and a half years, prior to the Seventh Trumpet, the ascension, the law will be ENFORCED.
Patricia � Bible Prophecy on the Web
http://groups.yahoo.com/group/BibleProphecy
