Consequences for Sin?

She has done an outrageous thing in Israel by being promiscuous while still in her father’s house. You must purge the evil from among you. Deuteronomy 22:21

This does not seem right. By 21st century standards this law is preposterous. God laid out that if a couple got married and the man accused his bride of not being a virgin—and it was determined that he was lying – he was fined 100 shekels (vs.19) for ruining her reputation. Then she was forced to stay married to him. If his allegations were proven to be true, she was stoned. I do not understand. Was this fair to the woman? Does God discriminate? Perhaps we have allowed so much ungodliness into our lives that we cannot grasp the importance of God’s emphasis on purging “the evil from among you.” All of this was to protect his people. I don’t understand the different punishments for the bride and the groom, but I do believe God to be fair and loving. So this is one of those things I will ask God in heaven. Until then, how can I “purge” ungodly things from my life? To judge God’s edicts but not change my life is foolishness – and dangerous. What do you think?