True praise and worship is accompanied by hearts that are obedient to the LORD. This psalm is a call to praise the LORD, to sing and be joyful and to heart and obey His voice.
Israel's sin and rebellion in the wilderness are put before us as an example. If we ignore the voice of the Holy Spirit, it will result in the hardening of our hearts. We will lose our sensitivity to His voice and His presence. Then our only hope will be punishment severe enough to wake us up.