Psalm 119 talks about God’s Law, His statues, precepts, decrees and commands. These were given to Israel who were under the Mosaic Law and who we expected to obey it.
Although we are not under that Law, but under grace, there is much that we can learn from the Psalm by way of application. However, out obedience to the Lord is out of love and gratitude for all that He has done for us in Christ Jesus our Saviour.