The idea of blessing God struck me in an odd way when I first heard it. But it is in the Bible, explicitly in Psalm 103
"Bless the Lord of my soul and all that is within me bless His holy name."
and Psalm 34
"I will bless the Lord at all times, his praise shall continually be in my mouth."
If God is perfectly content and happy why would he care if I blessed Him or not. If fact usually we are asking Him for blessing because we know that He is the source of all creation and blessing.
In most other religions people are desire blessings from God or gods to satisfy their appetites. The popular idea of heaven being the ultimate blessing of getting whatever you want all the time in a perfect paradise with God in charge is not at all biblical Christian. This concept seems to be in conflict with the biblical images of worship continually focused on God that we see in Revelation, Daniel and other prophetic books of the Bible.
A heaven that is all about me, it sounds kind of selfish when you think about it.
So does God need our worship or the blessing of our mouths?
NO- need is certainly not the right word!
But what happens when we bless the Lord and worship Him is that we experience the realm of heaven in our hearts. Heaven is in continuous worship of God. It is the irresistible response to being in His glorious presence.
Blessing and worship the LORD actually becomes a blessing unto us, much like giving blesses the giver not just the receiver. This reciprocity is why the author of the Psalms is so excited to bless the LORD. When he blesses God and speaks His praise there is a jubilation in his heart and I believe in the heart of God , our Father as well.
So Bless the LORD in song and experience the heart of heaven in your life.