Tim Challies recently shared his story, about The Most Important Thing his parents did when they were raising him:
"I saw my parents living out their faith even when I wasn’t supposed to be watching."While many oppose his thoughts (see the comments section), I wholeheartedly agree with him.
Of course, he (nor I) is not saying that there is a formula to your children making the choice to follow or reject the Lord. However, pursuing Jesus with your whole life is more important than anything you do for your child, in terms of their spiritual condition.
Even more, I would say that doing all kinds of spiritual tasks (taking them to church, signing them up for VBS, buying them Bibles, etc.) will be ultimately negated if they don't know that you trust in Jesus and follow Him.
When I was a Children's Pastor, I remember having a conversation with a young, single mom (who was questioning whether she should join a Small Group and serve in the church, because she was afraid it would take time away from her son. I told her, "The best way to become a better parent is to become a better disciple of Jesus."
I encourage you to read Challies' entire article, The Most Important Thing My Parents Did.
You can also read my thoughts on this topic, in these posts: