The message of the poem (by Khalil Gibran) is that your children are essentially nature's way of perpetuating the human species.
Although you are responsible for creating and nurturing them through childhood they are their own persons and not a piece of clay for you to shape as you wish in your own image. It is your responsibility to send them out fully prepared to face the world as they see fit and ready to live their own life in the way they want to live it.
They have to face a world that is changed from your world and will continue to change. Imposing your own ideas on how to live life would be backward looking.