The righteous have every reason to serve the LORD with gladness, as stated in verse two, because only they have come to know that The Great I AM (the LORD) is faithful (God). He is faithful to shepherd His flock, which means He brings them to drink fresh water, eat nutritious food, lead them to find refuge from the cold, and protection from predators.
In the spiritual sense God’s pasturing means providing godly teachers who preach His word faithfully and truthfully, for His glory and not for sorted gain. Such men protect God’s people from false teachers, religions, and ideologies.
God also provides within the context of a healthy church, godly brothers, and sisters who can give wise counsel during decision-making times. A sure way to cut your self off from God is to refuse wise counsel; to do so will make God very distant.
The Christian is one who can submit to godly counsel, continue in prayer and the fear of the Lord, and as a result can make a joyful shout to the Lord.