The Holy Spirit and faith

I know without the Holy Spirit we are blind, dead, enemies of God, so I'm just curious about the Holy Spirit's role in the Old Testament. I was listening to a pastor from another synod and it sounded like he thought the Holy Spirit wasn't responsible for creating faith during Old Testament times. Based on the conversation, I'm thinking he wasn't including the prophets, etc. I tried to do research on my own, but it seems like scholars are all over the place on the Holy Spirit's role before Pentecost. Can you tell me what our synod believes the Bible says regarding the Holy Spirit's work in Old Testament times?

In This We Believe, a statement of belief of WELS, we make this confession: “We believe that people cannot produce this justifying faith, or trust, in their own hearts, because ‘the man without the Spirit does not accept the things that come from the Spirit of God, for they are foolishness to him’ (1 Corinthians 2:14). In fact, ‘the sinful mind is hostile to God’ (Romans 8:7). It is the Holy Spirit who gives people faith to recognize that ‘Jesus is Lord’ (1 Corinthians 12:3). The Holy Spirit works this faith by means of the gospel (Romans 10:17). We believe, therefore, that a person’s conversion is entirely the work of God’s grace.”  [This link provides the context for that quotation.]

Conversion to saving faith has always been the work of the Holy Spirit. As the Holy Spirit changes hearts in New Testament times, so he did in the days of the Old Testament.