When in comes to spirituality I look at the solar 12th house of each.Pisces has solar 12th house in Aqua. This makes their spiritual outlook more eclectic, "weird", more about being connected to the bigger whole, unique and even hard for others to fully integrate and understand. As it seems so far out, so zany, shocking and never consistent.
Cancer has 12th house in Gem. They can think more about spirituality in terms of learning about all aspects and being more open minded and versatile.
Labels are difficult as well as "dos" and "donts". Often thinking of Godhead as more intellectual and mentally focused.
I would imagine books like Conversations with God, Abraham Hicks' "Law of Attraction" or "The Shack" tend to appeal because God "explains" and connects with the logical side of human nature.
Scorpio can be more accepting of the dual nature of God i.e the balance of light and dark and how it is always a constant conscious struggle.
With Libra on the 12th house in the solar chart, the belief of God as "holy" fighting off the "bad" is a one sided understanding of spiritual consciousness.
So theories of God/Satan as being two sides of the same coin, the light and dark existing side by side or God existing in both good and bad alike, is more acceptable to them.
Sagittarius has Scorpio as solar 12th house and is perhaps the.most extreme and fanatical of them all once one speaks of spiritual identity.
Sagittarius can wholly identify with one aspect whilst struggling to integrate or outright reject seeming contradictions to that one aspect that they deem to be the "true" and only nature of Godhead.
So when young God may be seen in one way and they will spread that "truth" and even force it down other people's throats.
But when older and Godhead is seen in another light, the former is rejected and seen as a part where they were "lost". And now that they have found "truth", everyone must be in agreement with that
The types of books that might appeal to them or worship places would be where there is an unequivocal differentiation between "right" and "wrong", saint vs sinner, evil vs good etc.
Many will speak of deception as somehow being cloaked as the truth. So they often will attack philosophies that are open ended in that and seem to be all inclusive.
Thats just my opinion.