I was just going to respond with 2 Tim. 3:16....only I would emphasize it this way:

2 Timothy 3:16 All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:

There are passages in Leviticus that are instructive for us in modern times. If someone asked whether God approves of tattoos or beastiality, we would find instruction in Leviticus 18 and 19, for example. Many are getting tattoos today because they think that prohibition is obsolete, only for Israel, etc. And we read news accounts of beastiality today and people wanting to marry their dogs, etc.

How does a Christian know right from wrong without the Law of God to inform their choices in life?

Another Scripture that comes to mind about the overall harmonization of Scripture is from the very book we are discussing here:

Jesus Christ, the same yesterday, today, and forever. (Hebrews 13:8).