The Ninth Commandment is, “You shall not bear false witness against your neighbour”.  To bear false witness means to tell a lie by giving untrue evidence when one is a witness in a Court of Law.  The Catechism explains this Commandment further by saying, “To keep…my tongue from evil speaking, lying, and slandering”. (1)

Lying

St Peter

Lying means saying, writing or acting what is untrue in order to deceive.  It may be a direct lie told from fear.  An example was when St Peter was in the courtyard of the high priest’s palace on Good Friday morning after Jesus had been arrested.  One of the bystanders accused Peter of being a disciple of Jesus.  And Peter said, “I do not know the man!” (NRSV, Matthew 26:74).  So people lie today to avoid getting into trouble.