Our hearts must be joyful day-to-day in the Lord, not because we have received anything special from Him, but because His love and mercy accompany us throughout our walk, so give thanks and praise His name.
That is why with we must praise God with songs, with this we are being grateful before God, and also our hearts will feel more than joyful. We must fully trust our God because He does not fail.
The best we can have is His mercy more than all things, because by His mercy we are here before Him today, so we must praise and rejoice in Him with all that we have. God is powerful and will never leave us.