This is the reputation required to enter chat across the entire Stack Exchange network, so convincing the powers-that-be that a change is required will not mean merely convincing us at Christianity.SE, but also the community at Meta Stack Exchange and the SE staff.
As for why the limit is 20 reputation, take a look at this related question: SO Chat: Why is it that “Only members of Stack Overflow with at least 20 reputation may talk…”? The short version is:
- The focus of Stack Exchange is asking and answering questions, not chatting, and a lower threshold would reduce that focus
- Addressing new user issues through comments on the main site, or questions on Meta, helps acclimate new users to how the site normally works, and is more visible (since not everyone participates in chat)
- A higher threshold prevents chat from getting as many spam or spam-like posts as we see on the main site
Our approach to helping new users should be to first leave comments and vote on their questions and answers. If they continue to struggle, a meta post may be in order (only 5 rep required for that).