Jesus did away with the old Mosaic Law given to Moses. However decades after Jesus died, early Christians along with the Pharisees decided to keep some of the laws. For a better understanding of the Mosaic Law and what is required for Christians see Acts 15.
True Christians who follow Jesus as their only authority don't feel they need to follow any Mosaic Laws. Matthew 28:18. This makes sense since apostasy began immediately after Jesus died. The Bible says that anyone who runs ahead of Jesus, and does not follow his teachings does not have God. 2 John 1: 9 - 11