The value of anything is determined by what someone is willing to pay for it. Jesus paid for our sins on the cross and He paid for our diseases and sicknesses at the whipping post.
Many Christians have been taught to change the word of God to match their experiences instead of believing God will change their experiences to match His word. To them the gospel is limited to only one benefit.
David admonishes us to remember all of God's benefits (plural). Psalm 103:2 (KJV) Then he tells us what those benefits are: God forgives all our iniquities, and He heals all our diseases.
It is good news that Jesus bore all our sins on the cross, but it is also good news that He bore our sicknesses and carried our pains, and by His stripes we are healed.
This is the great exchange many modern day churches have left out or tried to explain away. Because it is not being taught, many church members know nothing about it.
If that is where you are now, the good news is that you don't have to stay there! Faith is a choice, and you can choose to believe. Just as you chose to believe the gospel for remission of sins, you can also believe the gospel for healing and prosperity. No matter how little your faith is now in some areas, it can grow. God always honors genuine faith.