What are the motifs in Garden of Shadows by V.C. Andrews?

Religion is a recurring idea. Olivia has married for what she thought was love and later discovers she has entered into a marriage of convenience that is more of a job than a partnership. Olivia turns to the Bible to help her deal with the loneliness and depression that this realization brings her. Olivia becomes the mother of two children and later takes her husband's love child as her own. This helps Olivia, but when her two sons are killed, she finds herself once again turning to religion. Olivia's cousin, John Amos, comes to Foxworth Hall and helps her find consolation in the Bible.