When I was much younger I bought a motorcycle.  A small underpowered two cycle motorcycle without an oil injection system.  Not having an oil injection system meant that spark plug fouling was part of my life.  I used the motorcycle for a round trip commute of 100 miles on a daily basis.  Because of the fouling I had to carry extra spark plugs and on average once a week the bike would die and I'd be on the side of a road changing spark plugs.  Not an ideal situation but one I lived with for 2 years.

The problem was that my commute involved two different types of driving -highway driving and city driving.  Each type of driving required a different type of spark plug.  Since neither plug was designed to operate under the conditions I was using them for neither one fared well and ended up being discarded long before it's designer had intended.

Those spark plugs were just like me.  I was designed for a purpose.  When I operate in the mode I was designed for I do very well.  However when I don't, I do poorly.  This used to be a problem until I had a vision one day wherein the Spirit revealed to me that God designed me as a luxury car (Back then it was a Cadillac) to be driven over well maintained highways, but that I was stuck trying to drive this luxury car through a swamp (this was before SUV's and HUMMERS).

If we were designed to worship God we will only know peace and health worshiping Him.  Of course the Bible does say that God makes different vessels for different purposes so I'm not going to make a blanket statement that if you want peace you should make sure you spend time in worship.  But it does seem like a good place to start. :)