In typical David fashion, he begins this psalm in song and proclaims God's sacrifice and salvation. David proclaims again here how God is Almighty over heaven, hell, and all the world. Verse 6 is an invitation to all of the world. “O come, let us worship and bow down: let us kneel before the Lord our Maker.” Reiterates the fact that God created the world and everything in it. In verse 7 we are told, if we hear His voice, we will be His people. His voice comes to life through the Holy Spirit in the Word. Seek Him here and He shall be found.
Do not harden your heart to unbelief. The greatest gift we may have received is Faith. It allows to believe in Him and be the foundation for our lives. Without the Rock to stand on, where would we be tied down to? He provides the safety and security we all need if only we have FAITH in Him.