What is the ruling on the father of the wife working in the restoration and cleaning of churches, and is his money unlawful, and is it permissible for his in-laws and children to eat at his house?

Your wife's father is not permitted to work in churches, as this constitutes cooperation in sin and transgression, and the money he earns from this work is unlawful. As for eating from his wealth, if it is from his unlawful earnings from the church, then it is not permissible, because it is not good. However, if it is from his lawful earnings, then it is permissible for you. If it is mixed, and most of his wealth is from unlawful sources, then it must be avoided.