Does Romans 9:5 affirm that Jesus is God?

Yes, even though a number of translations wrongly render Romans 9:5b as an independent concluding doxology reading: God who is exalted above everything, be praised in eternity. Amen. There are a number of reasons, however, why such a translation ought to be rejected (see also the detailed discussion in Cranfield¹ and compare Légasse²). Firstly, in the Greek, Romans 9:5b is a subordinate clause to "Christ ... according to the flesh.” Romans 9:5b then begins with the words  who is (ho oon) as a further elaboration upon the foregoing. The phrase who is God over all must therefore necessarily refer to the person that had just been mentioned, namely Christ. If Paul had wanted to begin a new sentence, he would have had to begin it with the name of God (as new subject): God is over all… Secondly, an independent doxology would have to be isolated from what went before, but the reality is that the preceding material actually prepares the reader for a double statement about Christ: he not only comes out of Israel according to the flesh, but he is also God over all, blessed forever (cf. the construction in Romans 1:3–4: from David according to the flesh and the Son of God in power according to the Spirit of holiness). The preceding arguments are strengthened by this short summarizing statement proclaiming that none other than God himself became flesh in Israel! Thirdly, the counterargument that Paul hardly ever uses the name God (theos) for the person of Jesus³would only make sense if one assumes that Paul never acknowledged the divinity of Jesus, but the fact is that his letters undeniably prove that he does.^4,5