"Thou shalt not take the name of the LORD thy God in vain; for the LORD will not hold him guiltless that taketh his name in vain." (Exodus 20:7)
This is one of the Ten Commandments, of course, and is surely going to cause great consternation one day when men and women finally appear before God. Even Christians, too sensitive to use "God" or "Jesus" in careless or profane speech, often use such euphemisms as "gosh," or "gee," or similar expressions. Almost inadvertently, even conscientious Christians, when angered or pressed emotionally, feel constrained somehow to bring spiritual concepts into their exclamations--"for heaven's sake!", "son-of-a-gun!", etc., as well as other euphemisms such as "darn," "heck," and the like.
All of this, while deplorable, is nevertheless a sort of backhanded acknowledgement that God is real and biblical revelation is true. It is significant that adherents of other religions never take the names of their gods in vain! Who ever heard a Buddhist, or a Muslim, or a Hindu do such a thing? If they want to swear, they also will often inadvertently use the name of the true God, or His Christ, in vain. Even atheists frequently sprinkle their conversations with blasphemous Christian epithets, calling on God (who doesn't exist) to send someone to hell (which doesn't exist). "He that sitteth in the heavens shall laugh: the LORD shall have them in derision" (Psalm 2:4).
In this day of loose and vulgar speech, Christians need especially to control their own tongues. Jesus said, "But let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil |or, perhaps better, 'the evil one'|" (Matthew 5:37). Jesus has warned that "every idle word that men shall speak, they shall give account thereof in the day of judgment" (Matthew 12:36). HMM