Purchase a new Bible. Then, take a year to read through it with a Bible reading plan making notations in the margin written specifically to your child. Make comments about the verse’s special significance. Mention how you’ve seen a truth of scripture lived out in their life. Warn them of pitfalls. Encourage them with favorite verses underlined. Then, on their big day (graduation, 18th bday), wrap it up and give it to them as a gift.