Pope John Paul II wrote this Letter in 1994 to help guide the family in a tempestuous world according to its genuine light. It is actually quite a difficult read, so I have made a precis of it - which you can find here, then click on "Resources", then click on "Family".
The Letter expresses how the family is the hinge of the Civilisation of Love, and calls upon them to take part in God's plan. John Paul exposes the "other" plan for families for what it really is: an "anti-civilisation" based on the loss of truth and promoting an agenda which threatens the family to the core of its being. At the heart of the family is the mystery of the presence of the person of Christ. The Eucharist is the greatest expression of love in the family - for in Christ the family is redeemed.
This Letter is essential reading for spouses and parents, for your great task is to enable your family to be a part of the New Evangelisation.