Hi Samuel,
Sorry for the delayed response but I wanted to post a link to a sermon that might be helpful. It mainly deals with what’s “new” about the NC but specifically addresses the issue of non-believers partaking in the blessings of Christ. The sermon was delivered last Sunday evening at Reformation OPC in Apache Junction, AZ (right in your backyard). Pastor Joel Ellis, along with the church he ministers at, just recently came into in the OPC. He’s an extremely gifted preacher as you will see if if have time to listen. His background is calvanistic baptist so he is very familiar with that perspective. I hope it is a blessing to you as it was for me.