Ps 28:6-9 Praise be to the Lord, for he has heard my cry for mercy. 7 The Lord is my strength and my shield; my heart trusts in him, and I am helped. My heart leaps for joy and I will give thanks to him in song. 8 The Lord is the strength of his people, a fortress of salvation for his anointed one. 9 Save your people and bless your inheritance; be their shepherd and carry them forever.
David's worship is an overflow of gratitude because he experienced the Lord as his strength, shield, fortress and shepherd. Worship can never be just a matter of singing songs, no matter how technically or musically beautiful--without a personal experience of God, it's just a performance, not a ministry.
For David, the Lord was
(1) "my strength": There was an occasion when David was so depressed because his people wanted to stone him because they were so grieved at the loss of their wives & children, and Scripture tells us that David strengthened himself in the Lord: "And David was greatly distressed, for the people spoke of stoning him, because all the people were bitter in soul, each for his sons and daughters. But David strengthened himself in the Lord his God" (1 Sam 30:6). For David, spending time alone in God's presence was the way he renewed himself against all the mental & emotional pressures he experienced as a leader.
(2) "his shield": A shield protects us from the enemies' arrows and spears. Experiencing God as our shield means knowing the screening effect of His presence against attacks coming from human and demonic adversaries. When we are engaged in spiritual warfare, we need God's shield of protection against the devil's backlash & attacks.
(3) "a fortress": A fortress is a place of safety, security and peace. The Lord gives us rest and peace from constant anxiety. A fortress keeps the enemies out and God's presence in. When we know God as our fortress, we experience peace in the midst of threats -- whether they be spiritual, economic or whatever. We can sleep well because we know that the Lord is our fortress.
(4) "their shepherd": A shepherd is one who cares for his flock of sheep. He guides the flock to green pastures, clean water and keep out the wolves. We have a Guide, not a guide-book.
A story is told about a poetry society where poetry lovers gathered to read their favourite poems. A young man got up to read Psalm 23 beautifully and everyone applauded him when he finished. Following him, an elderly man got up and read Psalm 23, and everyone was moved to tears. The young man knew the Shepherd's Psalm, but old man knew the Shepherd. In the same vein, in worship, we need to know not just the Lord's Song well but the Lord Himself.
Thank You Lord for being our strength, shield, fortress and shepherd. For in You we find power, protection, peace and guidance. May our worship be an overflow of our experience of You as the Shepherd of our souls. Amen.