The following was written by a 28er
Spoiler
Preterism, open theism, and covenant theology are all rubbish, in that they are all non-Biblical. Acts 28:28 dispensationalism is not rubbish, since everything can be backed up by direct scriptural quotes and by comparing scripture with scripture.
From Abraham to Acts 28:28, there is no scripture that shows believing Gentiles being separate from Israel's program. During Acts, believing Gentiles were grafted into Israel. Before that, Gentiles had to become proselytes to participate in Israel's promises. Until Acts 28:28, Gentiles were never equal to Israel. However, in Paul's last 7 books, which cover the present age, Israel doesn't exist as a separate entity. Everyone is equal and individual in God's eyes.