I reviewed the bios of the previous contestants and the line of questioning did not change until Season 4. No one on Season 1 to 3 got a chance to show their spirituality and their 'religious' background.
My pick for Season 1 was Kelly Clarkson. It is only now that I was able to watch the show through AI Rewind. But I bought the videos on Season one, including Kelly and Justin's movie! 
And I bought Kelly's CDs 1 & 2 and her exclusive video.
Season 2, it was Carmen Rasmussen's charm and appeal that made me vote for her on that season. I have Carmen's mini CD. I bought their group CD and the Christmas CD of Season 1 and 2 contestants.
Season 3, I favored Diana De Garmo throughout the competition and I voted for her on the last few episodes of the show. I bought Diana's mini CD and the album. I also bought their group CD. Diana was 2nd to Fantasia.
Anyway, Season 4, first stop...
Anwar Robinson's ritual before performing, he said is to pray; he did not have a lucky charm when he was part of top 12; and he would have thanked God if he had won AI.
Bo Bice (he was my choice and fav on Season 4) - he prayed, a cross from his mom and a shield and he would have thanked God, his family and the crew of AI should he won. Runner up to Carrie was not too shabby. I bought Bo's mini CD and the full length Album.
Carrie Underwood - no ritual and no lucky charm; she thanked God and her parents when she won the coveted AI title.
Mikalah Gordon said she prayed, called her mom and pee'd; her rosary and her aunt's ring and God and her mother.
Nadia Turner said she prayed and her altoid, two nails intertwined that makes a cross and she would have thanked God.
Nikko Smith - he prayed and would have thanked Jesus.
Scott Saviol - he prayed and listened to some music, a pin with an angel and he would have thanked God.
Vonzel Solomon - she prayed and danced, an angel ornament prayed and blessed by her church and she would have thanked God, parents, family, friends and co-workers.
Season 5 - this is the season I was not really into AI anymore, but saw some top 10 performed.
Chris Daughtry -- would have thanked God and wife if he had won.
Elliott Yamin - he prayed and took deep breaths and would have thanked God and mom.
Kellie Pickler - prayed and would have thanked God, grandparents, friends and AI.
Lisa Tucker - said a prayer.
Mandisa - she prayed and vocalized and she would have thanked Jesus because He is so good to her.
Melissa McGhee- she prayed and would have thanked God and family.
Paris Bennett - she prayed and asked God to be her words and to let Him use her; and would have thanked God should she won.
Taylor Hicks - prayed and counted heads and he thanked God when he won AI.
For this season, I only bought a mini CD of Katherine McPhee. I voted for Kellie Pickler and then Katharine during the last few episodes of the show.