The church of England challenges its members to "adopt as an initial target the giving of 5% of their after tax income to and through the church, and a similar amount to other work that helps to build God’s kingdom". 
Should the church also encourage people to make these donations to impactful charities in order to use their talent well, given that there are great differences between the impact of different charities?

I also got an error message when I tried to sign up. I didn't fill in the CPR-nr. (Tax ID) field but I doubt that was the cause. This is what the message says:

Der opstod en serverfejl. Prøv venligst igen. Skriv til os på donation@giveffektivt.dk hvis problemet opstår igen. Hvis muligt, så fortæl gerne, hvordan man kan fremprovokere fejlen.

Thanks for your comment, lots of great insights.

I would place somewhat more emphasis on members of different Christian groups being more or less comfortable with the particular cultural practices of EA-C. For example, those from evangelical backgrounds are probably less likely to feel comfortable in a subculture that is often enthusiastic about recreational use of controlled psychoactive drugs.

Yeah, I would also imagine some Christians, especially more conservative ones, are being turned off by some cultural practices in (some) EA groups. And those who usually move in explicitly Christian social circles might find interacting with a secular community difficult regardless.

In the current meta, where longtermism is practically close enough to synonymous with x-risk reduction, any confident belief in the Second Coming may be sufficient to foreclose significant engagement with longtermism for many Christians. The Second Coming doesn't really work if there are no people left because the AI killed them all!

The eschatology question is interesting. I think it can still make sense to work on what amounts practically to x-risk prevention even when expecting humans to be around at the Second Coming of Christ (or some eschatological event in other religions). If God doesn't want humans to go extinct, he could achieve this through human efforts to mitigate potential x-risks – the idea of God implementing his plans through the actions of humans is a familiar theme from the Bible. Also, setting humanity on a path to self-destruction that could only be halted by the return of Christ definitely doesn't sound like the kind of thing God wants humans to do, so working against it would seem like a good thing.

But a belief in the Second Coming does reduce the size of the future (unless one expects it to occur very far away in the future), so it undermines the astronomical value of far future oriented interventions.

My guess is that EA reasoning about cause prio, rather than beliefs about the need to reduce animal suffering per se, would be the major stumbling block here.

I think you're right and it's the priorisation more than the cause itself, I should have been more clear about that.