our

What leads up to our verse is a very candid section that explains there is nothing special about us that we should be chosen:

1 Corinthians 1:26-27

For consider your calling, brothers: not many of you were wise according to worldly standards, not many were powerful, not many were of noble birth. 

But God chose what is foolish in the world to shame the wise; God chose what is weak in the world to shame the strong . . . so that no human being might boast in the presence of God.

With that in mind, our verse this week reads:

1 Corinthians 1:30

And because of him [God] you are in Christ Jesus, who became to us wisdom from

God, righteousness and sanctification and redemption,

The phrase "became to us" in Greek is two words "made" (ginomai) "our" (hēmin).  Yes, that second word is the possessive pronoun "our".

What God did was satisfy all the reasons that would have disqualified us, by giving us in the person of Jesus Christ all the things necessary.  The NIV makes this very clear.

1 Corinthians 1:30 (NIV)

It is because of him that you are in Christ Jesus, who has become for us wisdom from God—that is, our righteousness, holiness and redemption.