Satan is the Father of all liars. No liars will make it to heaven. When one lies under false pretense, they have left the faith. A Christian's conscience should bother them when they lie. If it does not bother one to lie, they have left the faith.
Christians are to know the truth.
No lie comes from the truth. Christians are to put away lying and to speak the truth. Christians are to have no enjoyment in lying. If a Christian does not keep their word, they are lying to God. A Christian's word is to be his bond.