you have to have heaven in you now to be there when you die 3

I wouldn't say buy it now (because it's a three-volume work and hence expensive...about 70 to 80 dollars), but there is one work of theology that is really a towering influence to be used for purposes of having material for meditation and visualization: Institutes of Elenctic Theology by Francis Turretin (1623-1687, Geneva, i.e. the source).

He covers everything, and it's the depth (the depth that the one-volume systematic theologies, as good as they can be, don't have) that is valuable for the meditation/visualization use. He is also scholastic in his approach which means, in this case, he has a clarity and intent to define and distinguish in as few words as needed. Each topic is broken down into its parts and can be seen fully.

But if you were to own Turretin's Institutes you would have the equivalent of the Bach Well-Tempered Clavier of theological works, so just for reasons of owning the greatest of its kind it would be worth having. And remember that I'm recommending it for practical purposes: for Biblical doctrine to be of course learned and understood as needed foundation, but to also be used for visualizing and awakening to new realities so as to be able to enter into them and be them. This is really a central, major act that separates people...