Who was God dealing with from the Old Testament through the early chapters of Acts?
From the Old Testament through Christ's earthly ministry and the early chapters of Acts, God was dealing with the nation of Israel under the Abrahamic covenant. Israel was God's earthly people, and their promises, Temple, and expectations were earthly rather than heavenly.
Les explains that all the way up through the Old Testament, God dealt with the nation of Israel under the Abrahamic covenant, including Christ's earthly ministry and the early chapters of Acts. Israel had only earthly promises and knew nothing of dying and going to heaven. Job spoke of his Redeemer standing on the earth in the latter days, not of seeing Him in heaven. Israel's Temple was in Jerusalem, and God resided there in the Shekinah glory. Les contrasts this with the Body of Christ, which is heavenly, connected to the Jerusalem which is in heaven. He notes a transition at Paul's commissioning to go to the Gentiles, when the Body of Christ is heavenly while Israel is earthly, leading finally to the thousand years when all earthly and heavenly things come under Christ's reign and rulership.