How to Deal with Parents Who Don't Pray?

It is upon you to continuously advise him and strive in it with an excellent manner and good speech. And it's obligatory that you do not leave because your presence with him is from the means of guiding him. Allāh, the Exalted said about the parents who are mushrikun (polytheists): "But if they (both) strive with you to make you join in worship with Me others that of which you have no knowledge, then obey them not, but behave with them in the world kindly." [Luqman, 31:15]. Therefore, Allāh commanded the son of the mushrikun (polytheists) to behave kindly with them in the dunyā and He did not command him to leave them. So you behave kindly with them in this world by speaking good, fulfilling their needs, and preparing for them food, drink and clothes. Advise him always and make dua for him in your sujūd, towards the end of your ṣalah, and during all times that Allāh guides him, bestows upon him tawfīq (success), and opens his heart to Imān. You should not leave him, but deal with them with excellent mannerisms and good speech with gentleness. Supplicate to Allah that He brings about its means (for his guidance). Also, find some good people whom he knows and respects, so that they come to him, advise him, and help you with the means of guiding him.