Romans 12:2

And do not be conformed to this world (any longer with its superficial values and customs), but be transformed and progressively change (as you mature spiritually) by the renewing of your mind, so that you may prove what the will of God is, that which is good and acceptable and perfect.  

Suppose our lives are not happy, peaceful, and lacking in joy. Check what we are thinking on. There will be days when strife caused by outside forces will try to play in our heads like a record skipping. Unplug the record player and plug it into the word. Put the word before the eyes, concentrate on Jesus, and tell the devil to git. Fight the good fight of faith.