Matthew 6:34

So do not be troubled about to-morrow; to-morrow will take care of itself. The day's own trouble is quite enough for the day.

Romans 12:11-12

never let your zeal flag; maintain the spiritual glow; serve the Lord;

Philippians 4:4-5

Rejoice in the Lord always. I will say it again, 'rejoice.'

Treasury of Scripture Knowledge

Summary

Wherefore I perceive that there is nothing better, than that a man should rejoice in his own works; for that is his portion: for who shall bring him to see what shall be after him?

Bible References

Nothing

Romans 12:11
never let your zeal flag; maintain the spiritual glow; serve the Lord;
Philippians 4:4
Rejoice in the Lord always. I will say it again, 'rejoice.'

Who

Matthew 6:34
So do not be troubled about to-morrow; to-morrow will take care of itself. The day's own trouble is quite enough for the day.