Loftus advocates an “outsider test” but, such a test is not wholly convincing. Being a disciple of Christ implies a relationship. One has to genuinely invest in the relationship through good times and bad for a longer period of time rather than shorter to have any real insight into it. It’s the spiritual equivalent to not judging a book by it’s cover. Some people claim they were devout Christians but still left Christianity. Unfortuantely, many people participate in works-based variations on Christianity. Works-based religions proceed from particular acts to a general state. Being a disciple of Christ works in the opposite way; from a general state to particular acts. Did the former Christian ever actually have a lasting relationship with God? I’m not sure if this is true of Loftus. The first chapter seems to indicate that he did not. Second, I would ask if the person was not able to keep up their end of the relationship and ended up leaving Christianity when faced with difficulties. Being a disciple of Christ is not easy and not everyone is cut out for it. God allows us to be tested and some people don’t have the wherewithal to withstand those tests, even if they have had a genuine relationship for a short period of time. The relationship with God is like a muscle; it has to be exercised to be strong enough to handle adversity and have endurance.
Loftus implies that American Christians don't test their faith by examining other beliefs and their reaction to Christianity; the outsider test. America has been religiously diverse for several decades. Americans are exposed to quite a few religions that are significantly different than Christianity. Consequently, Christians do have their faith tested by direct exposure to other religions especially given the fact that diversity is so prevalent in American education and media.
Moreover, it is possible for a person to find truth on the first try and therefore, not need to test that truth. The relevance to the outsider test is that a person might have a particular religion as an accident of birth but, if that religion is true, further testing will only serve to continually reinforce that truth. Consequently, the outsider test is not necessary to discover truth in every case.
Disciples of Christ recognize works-based religions and have no need to test each one. While the particulars of worship among them might vary based on culture, they basically function the same in that the adherent must perform a prescribed set of actions in order to remain in good standing. This means that a person does not need to travel the world sampling each religion. One works-based religion is going to be fundamentally similar to the others. Christianity, on the other hand, is unique among the world religions in several ways.
The religious pluralist is going to disagree with Loftus. One branch of pluralism maintains that all religions are basically saying the same thing. Another branch says that even though religions are saying different things, sincere adherents of each religion will all end up saved or a participant in the ultimate reality. Therefore, pluralism maintains that the “outsider test” is irrelevant.