Trust in the Lord with all your heart and lean not on your own understanding. (Proverbs 3:5). That’s the key to parenting your children—regardless of their stage in life!
In other words, all your parenting should be led by the Spirit.
You will do well to recognize and respect their differences. They are not you! They will do things differently than you did. Give them the opportunity to find their own way as you trust God to guide them.
You should share your wisdom and insight, of course. But do it without being critical. Let the Spirit be your guide as to when and how to say the things that He has shown you need to be said.
Be honest and open with them. Don’t feel like you have to always present yourself as the perfect parent who has never made mistakes.
Believe in your children in their adulthood. In your heart, always see them as the Spirit-filled, empowered Christian people of God they are called to be. Declare that status over their lives.
And, as you most likely did when they were young, relinquish your adult children to the Lord. Now, more than ever, you need to cast your care of them over on to Him. No matter how much you love and care for them, He loves and cares for them so much more.
Finally, let these words of Jesus be your guide about the lives of all your children, young or adult:
“Have faith in God.... whatever things you ask when you pray, believe that you receive them, and you will have them. And whenever you stand praying, if you have anything against anyone, forgive him” (Mark 11:22, 24-25)!