Hi Greg....You asked about the two witnesses and who they might be.  They are described as "the two olive trees" and "the two candlesticks."  The only definition that can be found in the Bible....and having ONLY the Bible interpret what the Bible says....is in Zechariah chapter 4.  There are some who have their own opinions on this, but for me, opinions don't count....only the Bible can tell us.  This article helped me understand who they are:

http://www.herealittletherealittle.net/index.cfm?page_name=2-Witnesses-in-Revelation

I hope this helps you understand who they are.  Nobody is resurrected from the past for this event....

YsiC,

Arlene