The Bible does not teach we do not need to obey any laws in Scripture - nor that we do not have to do any works. What it does teach is that the OT Law shows us that we are sinners in need of Saviour, and that there are no works we can do to merit salvation. However, as believers we are still required to obey the 10 commandments and the precepts in God's Word - if an OT command does not directly apply, there is still a principle or precept from it that does. There are many verses that teach believers (those who are saved) are to do good works in service to the Lord.

The Holy Spirit teaches through His Word, not apart from it.