The Christian God incentivizes the wrong things

[Esquilax]

...it's still possible to sin, repent, and then sin again... Part of Christian doctrine is that you will keep on sinning.

According to many Christians that is the case, but not all. In New Church doctrine repentance means to turn away from sin and not return to it. There are no 'magic words' and its more than just feeling regret full. Your whole being must change such that sin becomes aborant to you. What I meant earlier is that there are three degrees of repentance: a permanent change of heart, renewal of the mind, and manifest action.

Wouldn't this mean that it's possible not to sin at all, and therefore to be required to offer no repentance? One could just stroll straight from birth to the pearly gates without ever believing in god, under that logic.

Ah, but you're probably going to say that not believing in god is a sin, which rather renders your objection to the idea that we aren't required to only swear fealty to god (and feel really sorry for our thoughtcrimes! ) in order to be saved moot.