In the New testament, the same Greek word is translated testament and covenant.
If you are by Biblical definition a Christian then you have God’s Law written on your heart and in your mind. You can try to ignore it, but you can not get rid of it. You can say God’s Law is done away, but it will still be on your heart. There is only one way for you do do away with God’s Law.
1 Timothy 4:2 “Speaking lies in hypocrisy; having their conscience seared with a hot iron”.
Hebrews 10:16 “This is the covenant that I will make with them after those days, saith the Lord, I will put my Laws into their hearts, and in their minds will I write them”.