By giving rice one cannot convert a person. Even if he does the converted one cannot last long in the new faith. Changing the label is easy but changing the mindset is not. If you think that giving money and gifts one can convert the people, why don't you try to convert christians into hinduism? You know very well that you will fail in your attempt. If you think that people are converting for money why rich people are also converting? Giving tithe is only optional not compulsary one. The church is not dependent on human support it stands on God's support. Try to google to find out what the people converted into christianity are saying? Do not think in one angle.