OMA is a good charity to give to specific international Christian missions. I have been contributing through them to the Moscow Christian Evangelical Seminary for years. OMA and the Moscow Seminary are careful stewards of contributions, and they effectively promote the Gospel throughout the world.
Review from Guidestar
I gave $1000 and they did not give any promotional material. I started donations to them because a leading Christian witness and business man thinks highly enough of them to invest all his company profit in them. Knowing their background in advancing the Gospel, it seems one of the top places to give God's money.
Review from Guidestar
I gave $100 to OMS in Fall 2013. I then received a mailing from them that consisted of the following: a 31 page full color brochure, a full color trifold brochure, an 11-page full color brochure-style 2012 Annual Report, an ECFA pamphlet, a single color letter/receipt combo and an envelope. I really look for organizations that carefully steward resources. I never requested more information from them and found their mailing extraordinarily wasteful - from a financial and environmental aspect.
Review from Guidestar