It seems to me that this is another thread where you have embraced a "unique" view on a subject which the vast majority of conservative and Reformed scholars throughout several centuries dismiss it as erroneous. So, here we are with the old "fallen angels impregnating human women" fallacy! <img src="/forum/images/graemlins/rolleyes2.gif" alt="" />
MarieP thoughtfully pointed you to here: Who were these Sons of God? thread from 2004. There were many good replies to that question found there as there have been this time round as well. Thus, I shall not spend time repeating what I wrote in that previous thread but simply refer you to them via the link above.
I would also encourage you to read the relevant section in Commentary on the Old Testament Volume 1 by Keil & Delitsch (Eerdman's Publishing) on Gen. 6:1-4 since they are excellent exegetes of the Hebrew text. They see the "angelic" theory fanciful at best since there is NOTHING in the text as written that would warrant any such novel idea. (sic. my comments in the 2004 thread). Also, "Fred" mentioned H.C. Leupold's comments on this passage in his commentary Exposition of Genesis, vol 1, pp. 257-260. I have taken the trouble to scan it, convert it to PDF and attach it to this reply for download. <img src="/forum/images/graemlins/grin.gif" alt="" />