Fastest way to disprove tithing requirement

Marc Speed talks about the fastest way to disprove the tithing "Requirement" and what to say to a person who believes tithing is for today. Is the tithing law(s) given to Israel also binding on the church/christian conscience, or that Abraham tithed, should we; didn't Jesus command us to tithe?

Find out what your Bible actually says about tithing. Have you thought long and hard about what is a good work and what isn't? If the tithing law is part of the Mosaic covenant and we are not bound to be sanctified by the written law to salvation but through Jesus Christ propitiation work on the cross, then why are we still compelling the people of God to tithe as though it is a command of Christ?