What is the main conflict in The Thorn Birds by Colleen McCullough?

The main conflict in the novel revolves around the struggle between the spirit and the flesh.... Ralph's love for Meggie, and the way it opposes his ambition and love for the church.

The main conflict in the Thorn Birds is about a decision which father Ralph has to choose between his duty and lust.He's older than Meggie so he should have known what 's the accurate behaviour between him and her.(That's why man and woman can not be best friend)Human instin