“for the joy of the LORD is your strength.”
The “joy of the Lord” gives us a “key” to many other truths in God’s Word, and therefore it remains “our strength”. This joy will cause us to have compassion on others who have no such joy; it will add to our personal peace and favor with God; it will build our faith. One finds that when joy is ebbed, at a low, he loses, at least a portion of the desire to serve God whole-heartedly. I see, then, the truth of this passage, that the Joy of the Lord is indeed my strength. Oh that He would always, and forever, restore unto me the joy of my salvation!
Talking with God is prayer; His talking with us is a blessing.