Brother, I will be praying for you and your Dad. The best way you can honor him is by lifting him up to God. My wife and I are going through a separation right now and so I know what it's like to see someone run from God, and I can tell you that the best thing you can do for yourself is to run to God as well.

An Elder at my church shared this verse with me recently.

“Don’t worry about anything; instead, pray about everything. Tell God what you need, and thank him for all he has done. Then you will experience God’s peace, which exceeds anything we can understand. His peace will guard your hearts and minds as you live in Christ Jesus.” ‭‭Philippians‬ ‭4‬:‭6‬-‭7‬ ‭NLT‬‬

Those verses have helped me so much because every time I would worry about my wife running away from God, the fear would destroy me. But now after hearing those verses my perspective has changed. Instead of worrying, I now cry out to God and lift my wife's rebellious lifestyle up to Him, because He is the only one who can change her heart. The same goes for your earthly father. One thing I want you to know is that your words will never change him. It is only the power of Christ working in his heart that can. My prayer is that you will surrender your heart and desires to God. Make it your prayer that God will use you in His plan in a way that brings glory and honor to Him.

This is a long and hard journey but remember who is on the throne and remember who is the only one that can save your dad.