Joe,
Another thing we need to keep in mind is that the issue of divided families is also taught in the NT. That is not to say that God doesn't often work in whole families, for He certainly does, but sometimes He doesn't.

Luke 14:26 “If anyone comes to me and does not hate his own father and mother and wife and children and brothers and sisters, yes, and even his own life, he cannot be my disciple.

Matthew 10: 21 Brother will deliver brother over to death, and the father his child, and children will rise against parents and have them put to death, 22 and you will be hated by all for my name's sake. But the one who endures to the end will be saved...34 “Do not think that I have come to bring peace to the earth. I have not come to bring peace, but a sword. 35 For I have come to set a man against his father, and a daughter against her mother, and a daughter-in-law against her mother-in-law. 36 And a person's enemies will be those of his own household. 37 Whoever loves father or mother more than me is not worthy of me, and whoever loves son or daughter more than me is not worthy of me. 38 And whoever does not take his cross and follow me is not worthy of me. 39 Whoever finds his life will lose it, and whoever loses his life for my sake will find it.

John 7 2 Now the Jews' Feast of Booths was at hand. 3 So his brothers [2] said to him, “Leave here and go to Judea, that your disciples also may see the works you are doing. 4 For no one works in secret if he seeks to be known openly. If you do these things, show yourself to the world.” 5 For not even his brothers believed in him. 6 Jesus said to them, “My time has not yet come, but your time is always here. 7 The world cannot hate you, but it hates me because I testify about it that its works are evil. 8 You go up to the feast. I am not going up to this feast, for my time has not yet fully come.” 9 After saying this, he remained in Galilee.