"Man, that stinking witch...well, God requires that I love her, but she should have her sins exposed and man I'd like to punch her face!  If only everyone else knew what I know about her!"—an internal thought from a Christian.

"Oh yeah, well you don't really serve Christ; it's all for show with you [censored], go to HELL!"—a Christian phone call gone nasty.

"Whose mouth is full of cursing and bitterness.”—Romans 13:14; God.

The above are a symptom of sickness in the lives of Christians; the symptom of a deadly disease which carries with it a host of other maladies. It is called "bitterness," expressed in Greek as being "pikros," meaning that the entire thing is cutting, sharp.  Have you ever seen that sort of response from a Christian in a relationship? Calculated, incisive, meant to cause damage...here is something better to consider:

"Let all bitterness and wrath and anger and clamor and slander be put away from you, along with all malice."—Eph 4:31