At the end of life, parents can write a goodbye letter such as this to guide their children.
All children should grow up with parents who love and care for them. More than anything, that is what I want to do for you. I want to help you {practice skill/sport}, learn {educational subject} and find your way as a strong and passionate young adult.
Sometimes, though, God has different plans for us. Your {mother/father} will help you with all of those things and it will be my place to watch over you and protect you. I will be there to cheer you on in your triumphs and support you in your misery. You will be well loved. I will always be with you.
Look for me.