What does it say then?
Fellow citizens and saints with the household of God. The household of God would be Angels, who serve in the presence of God. We, both physically and spiritually alive, are citizens with the angels. That is pretty clear, and I am using the KJV.
What value is it to be a fellow citizen with angels, whether in flesh or spirit, if we can not aid another?
The first two words of that passage are "Now therefore," which means that what is coming next is explaining what was just written.
Verse 18 says "For through him we both have access by one Spirit unto the Father." If we have access to the Father, why go through Mary?
If we are fellow citizens and members of the household of God, why wouldn't He listen to us directly?
Verse 22 --"In whom ye also are builded together for an habitation of God through the Spirit." God Himself inhabits us--why would we--again--need or even want to go through another? He is right here with us. Talk to Him, not some other creation.
To address another point you seem to be implying, but actually coming out and saying--the recipients of the letter understood that Paul was not talking about those who have already gone on. He was talking strictly about living, breathing, Christians in Ephesia. That can also be translated to us--as long as we're living and breathing.