A person's world view affects how they rate this film. Believers are glad to find a fast-pace, engaging story, with a decent plot and a biblical world view. However, non-believers tend to be offended by the blatant Christian message and less forgiving of the low-budget CGI. Basically, the ratings are pretty much driven by each reviewer's worldview.
My two cents' worth? As a Christian screenwriter, I tend to be more objective than the average Christian viewer. Basically, going to film school took away a lot of the fun I used to have watching ANY film. Now I notice all the plot holes, pay-offs without set-ups, on-the-nose dialogue, character arcs that do not grow organically from the plotline, and a thousand other things that can go amiss in any poorly-crafted film. So, for me to rate this film a "6" is my way of saying, "Wow. Pretty good job!"
I don't know if this film will help anyone make a decision for Christ - wish I could know that. But as a Christian and a filmmaker, I found this fun to watch and uplifting. Not the best film ever made, but definitely not the worst! And that, I think, is the closest this film will ever get to having an honest review. IMHO, that is.