Deliver my soul, O Lord, from lying lips, from a deceitful tongue. Psalm 120:2
As Christians we are commanded to speak the truth (Eph 4:25). We are not to lie to one another in any respect because lying does not glorify God.
God's perspective on lies is very clear!
Lying lips are an abomination to the Lord, but those who deal faithfully are His delight. Proverbs 12:22
There are six things which the Lord hates, Yes, seven which are an abomination to Him: Haughty eyes, a lying tongue, and hands that shed innocent blood. Proverbs 6:16-17
Lying has terrible effects on relationships. Learning you have been lied to deals a serious blow to a friendship or a marriage because it breaks the trust that has been built in a person. Once a person has been caught in a lie we are immediately suspicious of everything they say. Lies cause us to question the integrity of the person who has deceived us and often we find ourselves looking around every corner to verify even the smallest thing they say or do is truthful.
One reason deception is so destructive is that is empties the bank of trust we have in a person we love. We enter into a relationship with a degree of trust that is either proven to be well placed and grows stronger or is proven to be mis-placed and decreases with time and revelations of lies. When the trust we have placed in someone is broken through deception few are willing to grant a "refill" on trust without some demonstration that they are worthy of that trust.
This is frequently misunderstood as being vengeful and bitter toward them, even though we have granted them forgiveness which is a biblical response. It is not vengeful to hold them accountable and to urge them to change, it is wise.
As in every case, we must seek to understand what the Lord would have us do, and how He would have us respond. We have the same two choices available to us as always, to glorify God or gratify the flesh.
Glorifying God means we forgive them for lying to us. As with any other sin issue, the choice is to respond biblically in a manner that will glorify God, or respond according to the desires of the flesh knowing that this will not bring God glory.
The godly response means forgiving the person who asks forgiveness for lies and deception. Many people are afraid to forgive a liar because they believe they are setting themselves up to be lied to again. They equate forgiveness with a restoration of trust which is not accurate. We can by God's grace forgive as we have been forgiven without restoring trust to its previous levels because trust is earned.
Trust is restored over time as a person's word is proven to be true. Your relationship will be restored and move forward. This would be the godly response to being lied to. It leads to life in the relationship and peace and unity. Follow the "trust but verify" method when you are lied to. Be sure tell the person that you want to trust them, but because of their lying to me you will have to have some evidence there has been change of heart. The evidence of heart change comes in life change.
As the heart is affected by the Holy Spirit working through the Word of God the liar will become a truth teller. Lies will become abhorrent to them, and they will begin to hate their former sin. They will be more concerned with honoring God than covering their own sin through lies. This is evidence of true repentance in a person's heart and life and is worthy of great rejoicing.