"The king shall joy in thy strength, O Lord." We are now kings in Christ's Kingdom. When Jesus succeeded in redeeming man, He delivered man out of darkness and placed him into His own Kingdom of Light. All believers saved by Christ are now declared as kings and priests. One characteristic of the king is his privilege to joy in the strength of the Lord. So often we see the alcoholic delivered from his bondage and led captive by the binding power of God's strength. We see the promiscuous teenager regenerated and kept through the power of God by His strength. If we saw all of the sins of a hundred Christians, past, present, and future, we would rejoice tremendously in the strength of God that cleansed them and declared their righteousness. Psalm 21 continues this way: God gives us, as kings, our heart's desire. We are led captive, and truly that is our heart's desire. He has supernaturally risen to the occasion and filled our life with gladness "more than in the time that their corn and their wine increased" (Psalm 4:7).
As we delight ourselves in the Lord, He will give us our heart's desire. Whatever the request, He meets that precious desire through Himself. He is faithful in the fellowship He has called us into. He will not withhold the request of our lips. Our words are nigh unto Him in the presence of His heavenly sanctuary. It is His pleasure to grant us the Kingdom, "to do exceedingly, abundantly above all that we ask or think" (Ephesians 3:20).