How do I parent an adult child?
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.