The Sacrament of Marriage is a vocation. Those called to this life giving vocation receive God's grace to strengthen them in their committment to each other and their family.  Married couples are called to model in their relationship the profound love that Christ has for the church.  By doing so, they not only set an example of sacrificial love for their children and grandchildren, they offer a beacon of hope to all those around them. that Love can indeed be transformitive and give us the courage to face life's greatest challenges.
Like all vocations, Marriage doesn't just happen in a moment. Throughout our lifetime it requires a million little moments of recommittment to that original "I do".  Over and over we are invited to say "Yes" for the sake of the other. These "Yes"es  will challenge us to wash dirty socks, welcome new life, move out of our comfort zone, forgive eachother, comfort eachother and so much more. Marriage can be work but it can also bring deep joy in the midst of the challenges.  
Below are some resources to help couples continue the work of of their vocation.