I find no matter how complex WTS theology is, you can always seem to pin it down to one or two sentences that have no bibical basis what so ever.
1. There is no such thing as " Spiritual Israel ".
2. No where does it say the member in the new covenant is limited.
The Old testament is the story of god and the jews and a series of convenants which made them gods people. Long story short the new testament is the story of the transfer of this convenant to the "church " the body of christ. Gods final arrangement with mankind to have a relationship with him though Jesus Christ. Believe it or not, that is the story of christianity