When I did my exposing of Ephesians 1:3-11, I visited Augustine, Thomas Aquinas, Martine Luther, John Calvin and Jonathan Edwards to see how they dealt with passage. Here is some of Calvin thoughts:
Wherever this good pleasure of God reigns, no good works are taken into account. The Apostle, indeed, does not follow out the antithesis, but it is to be understood, as he himself explains it in another passage, “Who has called us with a holy calling, not according to our works, but according to his own purpose and grace, which was given us in Christ Jesus before the world began,” (1 Tim. 2:9). We have already shown that the additional words, “that we might be holy,” remove every doubt.
If you say that he foresaw they would be holy, and therefore elected them, you invert the order of Paul. You may, therefore, safely infer, If he elected us that we might be holy, he did not elect us because he foresaw that we would be holy. The two things are evidently inconsistent—viz. that the pious owe it to election that they are holy, and yet attain to election by means of works. There is no force in the cavil to which they are ever recurring, that the Lord does not bestow election in recompense of preceding, but bestows it in consideration of future merits.
For when it is said that believers were elected that they might be holy, it is at the same time intimated that the holiness which was to be in them has its origin in election. And how can it be consistently said, that things derived from election are the cause of election? The very thing which the Apostle had said, he seems afterwards to confirm by adding, “According to his good pleasure which he has purposed in himself,” (Eph. 1:9); for the expression that God “purposed in himself,” is the same as if it had been said, that in forming his decree he considered nothing external to himself; and, accordingly, it is immediately subjoined, that the whole object contemplated in our election is, that “we should be to the praise of his glory.”
Calvin, J. (1997). Institutes of the Christian religion. Bellingham, WA: Logos Research Systems, Inc.(paragraphs added)