Psalm 66 contains several invitations that are tied to the word come: "come and sing"; "come and see"; and "come and hear." Let's look at the first two invitations.
The first invitation is come and sing, or praise the Lord. "Sing out the honor of His name; make His praise glorious" (v. 2). Sometimes we act as if praise is tedious. Sometimes we praise Him in a tired fashion. But the psalmist asks for glorious praise. Why? "Through the greatness of Your power Your enemies shall submit themselves to You. All the earth shall worship You and sing praises to You" (vv. 3,4). This is missionary zeal. We aren't to praise the Lord by ourselves. We come and sing, and we invite the whole world to join us.
The second invitation is come and see the works of God. Today people call the works of God natural law or scientific law. We try to explain everything, but we can't. Come and see the works of God--what happens in the heavens, what happens in your body and what happened in history. This is the work of God. I like verse 7: "He rules by His power forever." Satan is not ruling this world system--God is. He is allowing Satan to do some things, but He's going to use even that to glorify Himself. God is ruling by His power, and He will rule forever.
If you want to enjoy today, come and sing. If you've lost your song, come and see the works of the Lord. You'll be singing before long.
Have you lost your song of praise? Come and see the works of God; it will restore your song. His works reveal His greatness and His love. If you are walking with the Lord, praise Him and tell others what He is doing in your life.