Do you mean to say that each individual church can decide whether it will provide money to NCC and WCC? My understanding is that each conference is required to give a % of the collections of each of the churches in it's region
that is designated for NCC and WCC as well as other projects.
X would be able to tell you more accurately than I (he's an ordained elder in one of the Ohio conferences), but it's my understanding that individual members can specify where their tithes go, and can, as a congregation, vote to withhold apportionments.
Each individual church can decide where its money goes. The best way to do this is to pay specific line items of the apportioned money to those areas that one supports.
If the church doesn't vote additional money to the unpaid line items, then those items don't get funded.
Most methodist regions are in financial straits due to declining membership. If they are not now, they will soon become sensitive to targeted giving by the various congregations.
The Grammarian is correct that there is a large renewal movement within the UMC that is having significant impact. Because our polity only allows slow change, we are slowly changing for the better. Hang in there. The true gospel has prevailed at the last 5 or 6 General Conferences in a row with an INCREASING majority each time.