Spinoza's Ethics: I.P25:

God's essence is not distinct from existence, as its essence is existence. In contrast, modifications (affectiones) of substance, such as ourselves, go in and out of existence. Here, the essences of modifications are distinct from the existences of modifications. Further, the essences of modifications are not limited by duration. Earlier I discussed the concept of the virtual in which the essences of modifications inhere in contrast to the concept of the actual in which the essences come into and express God's existence as things. Spinoza's corollary articulates two forms of these things - as modifications of attributes or modes in which attributes are expressed. 

Deus non tantum est causa efficiens rerum existentiae sed etiam essentiae. 

Translated as,

God is not only the efficient cause of the existence of things, but also of their essence.

Demonstratio: Si negas, ergo rerum essentiae Deus non est cause adeoque (per axioma 4) potest rerum essentia sine Deo concipi: atqui hoc (per propositionem 15) est absurdum. Ergo rerum etiam essentiae Deus est causa. Q.E.D. 

Translated as,

If you might deny this, then God is not the cause of the essence of things and to such an extent (by A4) the essence of things can be conceived without God. But this (by P15) is absurd. Therefore God is also the cause of the essence of things.

Scholium: Haec propositio clarius sequitur ex propositione 16. Ex ea enim sequitur quod ex data natura divina tam rerum essentia quam existentia debeat necessario concludi et ut verbo dicam eo sensu quo Deus dicitur causa sui, etiam omnium rerum causa dicendus est, quod adhuc clarius ex sequenti corollario constabit.

Translated as,

This proposition follows more clearly from P16. For from that it follows that from given divine nature just as much the essence of things as their existence must necessarily be deduced and as I might say in a word in the same sense as God is called the cause of itself, so too should God be called the cause of all things. This will be established even more clearly from the following corollary.

Corollarium: Res particulares nihil sunt nisi Dei attributorum affectiones sive modi quibus Dei attributa certo et determinato modo exprimuntur. Demonstratio patet ex propositione 15 et definitione 5.

Translated as,

Particular things are nothing unless modification of God's attributes or modes by which God's attributes are expressed in a certain and determinate way. The demonstration is evident from P15 and D5.