I actually liked his performance quite a bit, he was really convincing... the problem I had was the length of the dialog he was forced to deliver. If the same thing delivered from a podium wouldn't seem out of place, it shouldn't be in the script... unless he's at a podium on screen (and even then I tend to frown).
I've actually spent a chunk of time thinking about the rhetorical strategy you're using (I agree with absolutely none of what you're saying, so I'll only comment on the argumentative structure of the piece). The approach is a novel one, avoiding the straightforward arguments that have been used for so long. Specifically here you never state that the character shouldn't be gay, just that since he is gay, to be a good christian, he should not pursue a gay lifestyle and choose god over a human relationship.
I do appreciate the way that you addressed his "coming out" and thought that was actually a delicate approach (although her reaction would have been much bigger if he were in a relationship with her) to have the rhetoric that lying about being gay hurts oneself and those around you... The alternative given, however, suggests that the only option that leads to happiness is celibacy and devotion. The presentation of this option is actually given in such a way that the viewer feels bad for the protagonist who will never be happy and for whom god becomes a second choice that is made under duress.
Rhetorically speaking, you've got a bunch of pieces that actually have quite a bit of value for your argument. You're not defaming the subject, but you are preaching to the choir... if this strategy is to work, you need to first build a rapport with the target audience (not the church nor the censors), then state your argument in a way that doesn't alienate them. A strong syllogistic argument is so close in this one... but you've got an enthymeme hurting your case.
Your syllogistic argument:
A: Having a hetero- relationship is hurtful in entered into under false pretenses
B: Having a homo- relationship is against the bible
Therefore,
C: Devotion is the only option remaining
Your C requires that the subject is specifically a christian already... without that, the bible doesn't hold the argumentative power that you need to make a solid argument. I've never found an argument that uses the bible as a source that holds up under rhetorical scrutiny and it's quite easy to find counter-arguments within the text itself (yes, I've read it cover to cover) to destabilize any argument using it as a source.
If your target audience is specifically Gay Christians, then these arguments may work (although not as drawn out as you're presenting here -- concision my friend), but will need specifics from the bible to hold any weight... and you should also make sure to do your research on the possible counter arguments and address them as well. However, it needs to be in the form of a short film rather than a filmed essay book on tape type of thing.
As was previously stated, Show, don't tell... this is a visual medium.