Helping Children to Cope With The Emotional Side of There Dad's Newly Diagnosed

About a week ago my children's father had tests run to detect what the doctors thought might be cancer. One of the tests came back this Easter weekend. It showed cancer in his lung and his back. HE WILL RECEIVE THE REST OF THE TEST RESULTS TODAY. I have been divorced from him for over 15 years. I do have a degree of a relationship to him still because of the children [aged 33,27,18], I also have a good relationship with his wife. If my heart is breaking over this what they must be going thru! WE have all prayed together and I have talked to there dad and let him know how many people were praying for him. My question is how do I help keep faith alive and how do I know the right time to talk and the right time to listen? My ex's wife just lost her mother to lung cancer a month ago and now has to deal with her husband and the same illness. Im really concerned for my children's emotional state. If there is any one out there that can offer any answers for any of us please write. God Bless Each One Of You Linda