I will thank You by living as I should.



To the natural man (unsaved) obedience is burden.  He might even call it legalism.  But notice David called obedience JOY in verse 2.  Jesus was obedient to the Father and notice what Hebrews 1:9 states:
You love justice and hate evil.
Therefore, O God, your God has anointed you,
pouring out the oil of joy on you more than on anyone else.”

This is why Jesus last commandment to His disciples was to
Matthew 28:19-20
Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe (keep, follow, obey) all things that I have commanded you; and lo, I am with you always, even to the end of the age.” Amen.   Note: A Christian is to obey Jesus' commands, not Old Testament law.  A lot of teachers nowadays do not understand the difference and they equate being obedient to Jesus as "Keeping the Law."  Not so.  
   Under the New Covenant we are new creatures, and this is evident by our new desire to obey Jesus and His commands.