What happens if you swear to tell the truth, but you don’t?

Answer:

Jesus stated, "Let your 'Yes' be 'Yes,' and your 'No,' 'No.' For whatever is more than these is from the evil one" (Matthew 5:37). In other words, a Christian should always tell the truth. There is no need for a Bible or swearing by a greater power. The reason people ask for these things is because of Satan's influence in the world. People, in general, have proven themselves to be untrustworthy. However, a Christian's word should be trustworthy with or without the extra props.

What happens to people who tell lies? "But the cowardly, unbelieving, abominable, murderers, sexually immoral, sorcerers, idolaters, and all liars shall have their part in the lake which burns with fire and brimstone, which is the second death" (Revelation 21:8). God doesn't consider lying any less of a sin than murder. It is people, wanting to excuse their misbehavior, who want to place lying as a "not so bad" sin.

Worse though, you backed up your lie by invoking the reputation of God. You used God's name to give credibility to your lie. How would you expect God to look at this? Under the Old Law, God stated, "If a man makes a vow to the LORD, or swears an oath to bind himself by some agreement, he shall not break his word; he shall do according to all that proceeds out of his mouth" (Numbers 30:2). The later it says, "That which has gone from your lips you shall keep and perform, for you voluntarily vowed to the LORD your God what you have promised with your mouth" (Deuteronomy 23:23). In other words, God didn't force you to use His Holy Name for your promise. You voluntarily offered it. Therefore, you had better keep your word. "When you make a vow to God, do not delay to pay it; for He has no pleasure in fools. Pay what you have vowed - better not to vow than to vow and not pay" (Ecclesiastes 5:4-5).

"Therefore, putting away lying, "Let each one of you speak truth with his neighbor," for we are members of one another" (Ephesians 4:25).

"Do not lie to one another, since you have put off the old man with his deeds, and have put on the new man who is renewed in knowledge according to the image of Him who created him" (Colossians 3:9-10).

What should you do? First, you need to repent of your sin. "Now I rejoice, not that you were made sorry, but that your sorrow led to repentance. For you were made sorry in a godly manner, that you might suffer loss from us in nothing. For godly sorrow produces repentance leading to salvation, not to be regretted; but the sorrow of the world produces death" (II Corinthians 7:9-10), Repentance is from an old Greek military word that literally means to do an "about face." You did something wrong, now it is time to turn around and start doing what is right. You will have to give up lying, but more you need to fix the problems, as best you can, caused by your past lies. "Or observe this very thing, that you sorrowed in a godly manner: What diligence it produced in you, what clearing of yourselves, what indignation, what fear, what vehement desire, what zeal, what vindication! In all things you proved yourselves to be clear in this matter" (II Corinthians 7:11).

Next, you need to make matters right with God. If you haven't become a Christian, you need to do so. If you are a Christian, you need to pray to God for forgiveness.