How Is Access to God in the New Covenant Different from the Old Covenant?

Questions about how access to God through Jesus in the New Covenant differs from access in the Old Covenant, whether the salvation of Gentiles is just a means to the end of making Israel jealous, and the idea that theology is only personal and contextual, not objective.

• How is access to God through Jesus in the New Covenant different from the access Jews had to God in the Old Covenant?
• Is the salvation of Gentiles just a means to the end of making Israel jealous (see Romans 11:11–16)? How is this supposed to make us Gentiles feel?
• How would you respond to someone who said, “Theology is personal and interpersonal work, so don’t believe claims that any theology is objective; it’s all personal and interpersonal and contextual”?