By all means we should give to the Church, but we are not under a legal obligation to tithe.
Each man should give what he has decided in his heart to give, not reluctantly or under compulsion, for God loves a cheerful giver.
2 Cor 9:7
There is no obligation to tithe, and the Landover practice of ranking your parishioners according to the level of giving is thoroughly anti-scriptural and contrary to the universal priesthood of all believers.