Lying or not telling the truth is what we as Christians know as breaking covenant or a commandment given by God. It is one of the Ten Commandments not to bear false witness or lie. People lie because of sin. Sin has set all evil into motion. The Bible teaches us that those who practice lying are of their father the devil and that he was a liar from the very beginning. If we know that we have committed this offense, the thing to do is to repent to God and ask for forgiveness and He is faithful and just to forgive us and cleanse of from this unrighteous behavior. Our conscience is the part of our souls that judges right from wrong and it does let us know that lying is wrong. Then we have the words of Jesus when it comes to lies that other tell us, or we may be guilty of too. He said, if we are without sin to cast the first stone at them, but if we consider ourselves and that we are not exempt from behavioral flaws, we are practicing, and going on our way and to sin no more. Not to practice this behavior because it is not good. God is not a man that He should lie, we are human, but we are desiring the character of God.