Inheritance and adult child
Is it wrong to disinherit an adult child that is living in open and unrepented sin and you know that the money would be used for sinful habits? God says that we need to be good stewards and leave an inheritance for our children. Would it not be better to leave that money to a church or another area that would help the spreading of the gospel?
In the Bible God has not specified precisely how we are to distribute, at death, the possessions he has entrusted to us. He allows us to make those decisions in Christian love and wisdom.
If you are of the opinion that it would not be beneficial or helpful for an adult child to receive money through your inheritance, then your thought of redirecting your assets elsewhere is understandable. There is nothing unscriptural about that intended course of action.
Even though I do not know your situation, I would encourage repeated efforts to address and try to resolve the obstacles that have you thinking of disinheriting your child. If you follow through on that plan, ill will in family relations could very likely result. Clear communication with your child will be most helpful—for the present and the future.
If you are in need of resources for estate planning, WELS Ministry of Christian Giving offers an estate planning guide. This link will take you to that guide. God bless you and your family.