What is the ruling on hating a close relative who is a thief, a liar, a hypocrite, and two-faced, and how should one deal with him if he is ignorant and foolish, turning advice into argument and animosity? And are we sinful for not advising him?

You should advise the foolish and disobedient relative and forbid them from evil with gentleness and kindness. If they are guided, you will have a great reward. The Prophet, peace and blessings be upon him, said: "Religion is 'Naseeha' (sincere advice)." A Muslim is required to denounce evil and change it with their hand or tongue; if they cannot, then with their heart, which is the weakest of faith. If advice does not work, then your dislike and hatred should be for their action and disobedience. It is better not to boycott them unless there is a benefit or as a means of pressure for them to return [to righteousness].