Is it all right when mad to say "gosh" or "darn"?
What do we mean by “all right”? If I am asking about whether or not I can get away with saying it I have the wrong perspective to begin with. Paul points out to the Corinthian church, in 1 Corinthians 10:23-33 that instead of asking if something is permitted by the law, I should ask if it is beneficial to God, to others, and to me.
It is not "all right," but neither is it so horrible that God can't love you anymore if you say those words. It is a bad habit that must be overcome through prayer and God's help.
“Gosh” is a gentler way of saying “God” and “darn” is the nice way of saying “damn”. These are used separately or together to express anger, surprise, hurt and fear. The words themselves are not a problem but the way they are used can be.
“Gosh,” meaning “God,” is spoken to in the third commandment of Exodus 20. "You shall not take the name of the Lord your God in vain." This commandment does not prohibit saying God's name; rather, it prohibits doing it in a way that empties it of its value and worth. Notice most people who say this, in either form, generally are not trying to insult God. Rather, the expression indicates that He just isn't anything important to them. Saying “gosh” suggests that His name has fallen to just a trite way to express a negative emotion.
“Darn” is a bit different because there is no such commandment about its use. In fact, the Bible talks a lot about damnation. The best way to view this is to recognize that “damn” is usually said in a situation when something doesn't go your way or it hurts you. The comment, "damn it," is a silly phrase for the believer to say. We should instead say, "God, bless it."
The believer who responds in the former way is not guilty of a deep, dark sin; he is just immature. Just as it is unbecoming of a believer to curse people (James 3:9-10) so it would be to curse situations (Phil. 4:13.) Though it is not nearly as bad as cursing people, cursing situations leads to defeat in our lives. Believers are told to rejoice in trials and temptations because God will work them to our good.