As a believer you are responsible for your home and children as part of your testimony Parents are to raise children in the Lord's fear and love (Ephesians 6:4). Smoking and consuming alcoholic beverages are clearly inconsistent with Christian testimony (Colossians 3:5 and 1 Peter 4:3). While you cannot change your in-law's behavior, you can control the sphere of your responsibility. It is better that you kindly and clearly inform any invited guests who may normally smoke or drink alcohol that you have established principles in your family refraining from these. Ask them to respect your rules (1 Timothy 3:4). Consistency with your convictions will make a definite impression and provoke consideration of your faith and devotion.