A heart at peace gives life to the body, but envy rots the bones.
How many things do we compare when it comes to others;
Money/wealth and the things they own
Athletic ability (for some, this have never changed since high school)
Public speaking ability
How about the CHRISTIAN comparisons?
Bible reading and how much of the Bible they know
Prayer and how much time they spend in prayer
Ability to pray in public
Comparison is an evil weed that can spring up in the life of anyone who gets their eyes off of themselves and the plan God has for them and on the life of another individual. The reason why Jesus talked about us keeping our eyes on him was as much about not looking at others peaks and valleys as it was to help give us strength on this earth and the challenges he knew we would face.
Think of it this way, our lives already have struggles without us making things worse by comparing what we do with others. I just got back from a Moab hiking trip last week. If I only kept my eyes on the guys I was with and not on the path I was walked, I would have tripped and never made it out of some of the canyons we hiked. We can't complain that our walk with God is too tough if we don’t keep our eyes on Jesus for guidance and the path for the journey.
God’s plan for you is not wrapped in the life of another person and the quicker we figure that out, the more at peace we will be in ourselves, and the healthier our bones will be!