This is the last chapter of Psalms as given to us in God’s inspirited canon of Scripture. In this chapter, we will note that verse 1 is about where we praise God, verse 2 is about the why we praise God, verses 3-5 are about how we praise God, verse 6 focuses on the whom again and the chapter ends with another what.
Starting in verse 1, the chapter begins, “Praise ye the LORD”. That would be a “what” question in “What does God call us to do?” Answer: Praise Him.
The rest of the verse talks about where to praise Him. I could paraphrase this verse by stating we should praise God on earth and in heaven. Yes, that is another call for all creatures, including angels to praise God. I also see this as reminder to us that we should praise Him now, because we will continue to do so in heaven.
We do not necessarily praise God 24/7 in heaven (Yes, I realize there are not clocks in heaven as time does not exist there as is does here). However, I think we should get used to the idea of praising Him now, to regularly remind ourselves that He is there and He is not only guiding us, but providing us with the ability to do His will by that praise.
 Praise Him for His mighty acts: praise Him according to His excellent greatness.
Speaking of the why or for what reason we should praise Him, I see in verse 2 that we should praise Him for His mighty acts and His surpassing greatness. Actually a better question for verse 2 is not “why”, but “for what reason” should we praise Him?
The Bible records various acts of power He did as witnessed by His many miracles recorded throughout the Gospels. However, His greatest miracle was drawing us out of this world and saving us from sin. That alone is a mighty act of power we can appreciate. Not only has He saved us but He has done many good things in our lives since salvation.
The second half of this verse calls us to praise Him for His “surpassing greatness”. Think of it this way: God can do things that no other so called god or no other creature including man can do. In other words, be grateful for the good things that God has done in our lives.