Prostrate

is one of the best active Mantra generators, as getting the free block on cast can make this a fine pick in the early game. However, the low amount of Mantra given (2, or 3 when upgraded) means that it's very difficult to enter Divinity off of just Prostrate alone.
Ultimately, one of the best ways to consider Divinity cards is to consider how many cycles through your deck it takes to achieve Divinity. For example, a card that gives 3 mantra takes 4 deck cycles to reach Divinity, while a card that gives 4 mantra would take 3 deck cycles. Thus, you should ultimately achieve to have your mantra cards give a total of either 5 or 10 mantra each deck cycle. and can also help with this. As an example of a great Divinity deck, a deck with an upgraded , a , and a can easily achieve 10 Mantra in just 2-3 turns.