Motivation to Meditate on the Law

If you regularly study and meditate on the Scriptures, how do you respond when the passage you are reading is part of the OT law? What are some of the unique challenges that come when we seek to meditate on these portions of the Scriptures?
How can we respond when someone ridicules the Bible by quoting Old Testament dietary laws, laws regulating slavery, or other OT rules that seem outdated, bizarre, and even immoral in our culture?
The author of Hebrews tells followers of Jesus that the law covenant of the Old Testament is “obsolete” and soon to disappear (Heb. 8:13) but we are also told that ALL Scripture is inspired and profitable (II Tim 3:16). In what ways can we benefit from studying a portion of Scripture that is no longer directly applicable to us?
What perspective do you think enabled the OT writers to “delight” in the law, to “exceedingly love” the law, to be “consumed with longing” for the law? Spend some time pondering Ps 119