More than 40 years ago I was a religious cultural Christian. I grew up attending church twice on Sunday, Christian schools, teaching Sunday school, serving, giving but I didn't fully love God. I said I did and I thought I did, but I'm confident God thought otherwise.
After being told I had non-hodgkins lymphoma and had 5-9 years to live I was convicted by the Holy Spirit that while I "believed" at some level, I did not have enough faith to live for God. I knew there was a problem but I didn't know what to do about it.
A pastor friend suggested I let God tell me what was missing. He challenged me to read the Book of Luke over the next month, "28 chapters, a chapter a day". But Clare before you read each day, pray this prayer:
God, today please teach me everything you want me to know and give me the courage to live like I believed it.
It's the "living like I believed it" requirement that did me in. All my life I "believed" everything I read or heard about God. I believed it was true but I did not want to live that way personally. Saving faith is the application of biblical truth. We aren't saved by obedience, but neither can we be saved without it. The Holy Spirit "spoke" to me through my reading and convicted me that unless I was willing to follow Jesus the way he required, I was spiritually lost. I could no longer live under the illusion that I was a Christian based on my theological beliefs alone and lukewarm obedience. The false sense of security was gone and stood naked before Jesus.
I'm sad that I didn't respond immediately to live for God. I spent six months just "sniffing around the trap," desperately trying to find Plan B, a less costly less intrusive way to be a true Christian without having to completly change my thinking about almost everything in my life. I couldn't because Plan B doesn't exist for any would-be follower of Jesus.
Perhaps you have older kids or adult children who haven't actually walked away from Christianity but there's no fire in their belly for God. But like I did, they believe they are Christians. How about asking them to give you this gift for Christmas; Read the Book of Luke over the next month, praying the prayer I was challenged to pray and then let's have a cup of coffee together. "Tell me what you learned that you didn't know before". No preaching. Just ask them that question.
Let the Holy Spirit through the Book of Luke, speak to your child.
"My word will not return void.... " Isaiah 55:11