In the book of John (1) Jesus says, "It is written in the prophets, 'And they will all be taught by God". Jesus is quoting from Isaiah(2) where God speaks to the Israelites who have come out of Babylonian captivity, "And all thy children shall be taught of the LORD; and great shall be the peace of thy children".
Jesus continues(3) saying, "Everyone who hears and learns from the Father comes to me". Jesus is clearly saying here that if we and our children learn from the Father Himself we will be drawn to Jesus.
For your family members to remain in the faith and to come to the saving knowledge of His Son, to have them instructed by the Lord as they come out of sins captivity, pray that He PERSONALLY teach your family because He is a Teacher second to none!
(1) : John 6:45a
(2): Isaiah 54:13
(3) : John 6:45b