and. Note the Figure of speech Polysyndeton (App-6).
the dead = dead people. See App-139. (without the Article).
the living = living people. The only conclusion being that they must rise and live again in resurrection in order that He may be their God. This is what the Lord set out to prove (in Mat_22:31) "concerning the resurrection". Greek. zao. See note on Mat_9:18.