Git: Any way to set default login credentials?

Setup your ssh keys appropriately with empty passphrase and you need not enter the credentials: http://help.github.com/mac-set-up-git/

From your description of things, it sounds like your [Project Dir]/.git/config file is setup with the line url = https..., and not url = [email protected].... Can you check that file to see what it says? It'd be great if you could post your entire "remote origin" section. It probably looks something like this:

[remote "origin"]
    url = https://github.com/atheycreek/churchdeploy.git
    fetch = +refs/heads/*:refs/remotes/origin/*

but needs to use ssh instead of http like this:

[remote "origin"]
    url = [email protected]:atheycreek/churchdeploy.git
    fetch = +refs/heads/*:refs/remotes/origin/*