For those who like to use Galatians to prove that the "law was abolished at the cross," please check out our rebuttal.
How should we deal with people who mock YHWH and His Torah? There are people who think it's irrelevant to abstain from unclean foods (pork, shrimp, etc.), not deface our bodies (Leviticus 19:28) and immoral behavior (1 Corinthians 6:18).
GREAT question, Kevin! What I always do is send them the link to my Christian Questionnaire: http://therefinersfire.org/initial_christian_questionnaire.htm If they don't wish to check it out, then I have nothing further to say to them. Let them tell it to God on Judgment Day!