BQ: If a seemingly healthy Christian is prone to swearing when upset, it reveals a sickness beneath the surface. The words we say when upset are often an indicator of our deeper, truer spiritual health. 

No matter how healthy we seem on the outside,  "the mouth speaks out of that which fills the heart.  The good man brings out of his good treasure what is good; and the evil man brings out of his evil treasure what is evil." (Mt 12:34-35)

The truth is, if "from the same mouth come both blessing and cursing...these things ought not to be this way."  (James 3:10-12)