Nice initiative! but how do you plan to do this?
Mind you, the members can be skeptical (for good reasons) plus we have seen donation scams popping every now and then. Hence, before anything else, I suggest presenting a plan on how do you prevent their money from going to someone else's vacation trip.
First of all I think if it is possible then everyone's donation amount can be distributed to everyone in one place. But since the amount of fraud is so high nowadays, it will be very difficult to collect all the money. There is another way if we all help the needy people around us according to our ability rather than pooling money. Then there will be no fear of being cheated in everyone's mind.
they can distribute a portion of the profit earned through their investment to the poor and needy if they wish. That is, help the underprivileged people through Bitcoin.
This situation is very suit for this idiom.
Give a Man a Fish, and You Feed Him for a Day. Teach a Man To Fish, and You Feed Him for a Lifetime
But you're talking about Muslims here, most of Muslims don't want to get involved with Bitcoin even though you're already convert it to fiat. So if you're want to make a donation or give a food for them, make sure you already tell them if the money or food come from Bitcoin and let them decide to receive or reject your offer.
Teaching them about Bitcoin looks not possible too.
Our plan is to help the poor and underprivileged people scattered around us. I don't think Bitcoin will pose much of a barrier to them here. Because we are doing things thinking about the welfare of people.