One glaring thing about Christianity is that it is a call to battle! Accepting Christ is openly declaring that you are an enemy of satan, the prince and ruler of this world, who will deploy every weapon against you. That is why Jesus prepared us in advance in John16:33 that we would face tough times here on earth: attacks on our job, business, home, finance, health and everything we represent. He said this so we would not be troubled but cheerful when we pass though crises.
But we murmur and complain, even as Christians! Yet we ask for the will of God! What really is the will of God? [KJV] Hebrews 10:36 “For ye have need of patience, that, after ye have done the will of God, ye might receive the promise.”
We hear the “will of God”, what is the “will” of God?
Jesus, in Matthew 6, asked us to pray and enforce the will of God here on earth. What are we to pray and enforce here on earth? The “will” of God! Which is? CHEERFULNESS!
It does not matter what you are passing through, what you are experiencing, what others do to you or say about you. No! Be Cheerful! Be merry! Be full of celebration!  “Rejoice evermore.” – 1 Thessalonians 5:16
I can’t imagine a sad soul or heart in heaven!
We are commanded to live here on earth as though we are in heaven. If sad people cannot be found in heaven; if heaven is a place for only cheerful and happy people then this is what is expected of us Christians here on earth, irrespective of our experience!
The nature of God which we are called to share or partake with Him (2 Peter 1:4), can only be stirred up with joy, a segment of the fruit of the Spirit. The nature of God in us is stifled when we are grumpy; murmuring and complaining. We become short-fussed, ill-tempered and angry with everyone and everything when we lack joy. And in that attitude, we make mistakes and worsen things.
“A merry heart doeth good like a medicine: but a broken spirit drieth the bones.” – Proverbs 17:22
Good health, sound mind, prosperity, good success and godliness are fruits of a merry or cheerful heart. A sound mind can think and plan, it can draw physical strength from the Lord to accomplish tasks, it boosts the immunity of the person  against sicknesses and diseases.
The power and ability of God is made manifest as we rejoice. Laughter, they say, is the best medicine. Rejoicing always – evermore, is the key to unlocking the nature of God in us.