When told to deliver a package to a vicious mob boss, a desperate young Christian woman steals a car and finds herself menaced by a deranged truck driver pursuing her car across country roads, forcing her to devise a plan that would save her and her little brother held by the mob boss from death

As noted, the logline seems to have two antagonists. And if the package is that important to the mob boss, why would he entrust it to her to deliver instead of a trusted, competent minion?

Why christian? It seems like this adjective has no relation to the story.

I agree with the previous comment.
In other words, you should build a single cause-effect pathway: in your logline the truck driver has no relation with the drug story. You should create a clear connection between the track driver and the drug buisiness.