First, I think it would be good to ask, Does the Lord ever show favoritism?  The answer is NO.  We have the words of the Apostle Paul in Romans 2:11, “For there is no respect of persons with God.”  We have the words of the Apostle Peter in Acts 10:34, “Then Peter opened his mouth, and said, Of a truth I perceive that God is no respecter of persons.”  This means that the Lord does not prefer some people over others.  However, Peter goes on to say in verse 35, “But in every nation he that feareth him, and worketh righteousness, is accepted with him.”  Those who believe on the Lord Jesus Christ and, as a result of that faith, do righteous deeds, these people are accepted by God.  They are saved and belong to the Church of God and thus are favored by God. 

Giving leniency is defined as showing mercy.  We read in Psalm 103:8, “The LORD is merciful and gracious, slow to anger, and plenteous in mercy.”  While we should follow the example the Lord set for us, we need to understand that to disregard or tolerate sin in ourselves or others is not mercy.  We read in Isaiah 59:1-2, “Behold, the LORD’S hand is not shortened, that it cannot save; neither his ear heavy, that it cannot hear: But YOUR INIQUITIES HAVE SEPARATED BETWEEN YOU AND YOUR GOD, and your sins have hid his face from you, that he will not hear.”  God hates sin and He hates the occasion of sin among His people.  Sin will greatly interfere with our relationship with the Lord.  Psalm 66:18 tells us, “If I regard iniquity in my heart, the Lord will not hear me.”  For someone to overlook the sin in someone else, and not warn them about the consequences of their actions, is to do an injustice to that person. 

You did the correct thing in speaking privately with your pastor about your concerns.  It seems he did not listen to you.  What should you do next?  We read of how to handle such matters in Matthew 18:15-17, “Moreover if thy brother shall trespass against thee, go and tell him his fault between thee and him alone: if he shall hear thee, thou hast gained thy brother. But if he will not hear thee, then take with thee one or two more, that in the mouth of two or three witnesses every word may be established. And if he shall neglect to hear them, tell it unto the church: but if he neglect to hear the church, let him be unto thee as an heathen man and a publican.”  Since you have already spoken to him, you should now ask one or two more people in your church group to join you in addressing this issue with him once again.  If he refuses to listen to you and your group, then you should take the matter before the church so that all may seek to help him with his actions and his attitude. 

I suppose one of the greatest dangers here is that his son continues in his sin and feels justified because his dad backs him up in his sinful deeds.  How sad to think that this young boy could grow up to live a life of sin because his dad would not correct him when he needed correction.  Perhaps one of the elders among you would be led of the Lord to speak to this young man and lovingly correct him of his sinful ways.  Galatians 6:1 instructs us, “Brethren, if a man be overtaken in a fault, ye which are spiritual, restore such an one in the spirit of meekness; considering thyself, lest thou also be tempted.”  (468.4)