eph 2:1

 Is there any reason anyone can think of as to why most translations of Eph.
 2:1 translate the present participle ontas as were instead of being? This
 could be then rendered:

 and you being dead-ones by the trespasses and the sins of ye--instrumental--


 and you being dead-ones with reference to the trespasses and with reference
 to the sins of ye---dative---

 Due to the context I would prefer the first choice because down in verse 5
 we have the same thought continued though rectified - and being-ontas-us
 dead-ones by the trespasses He-jointly-made-alive-(us)with the Christ....

 I've always wondered about this and perhaps someone could enlighten me.

 Any thoughts?                         Thanks,
				     Peter Cepuch