1 Cor 8:5-6 Indeed, even though there may be so-called gods in heaven or on earth—as in fact there are many gods and many lords— yet for us there is one God, the Father, from whom are all things and for whom we exist, and one Lord, Jesus Christ, through whom are all things and through whom we exist.One God and one Lord. Paul keeps the two quite distinct throughout his writings. The way he writes about them is different. They do different things. They want different things from humanity. In fact, the sense I get is that Paul emphasises their difference more than he writes about their unity. The unity of God the Father with the Lord Jesus Christ and with the Holy Spirit appears to come more from Johannine sources.
But what's the difference? Something I'm thinking about is whether, for Paul, God the Father is power without authority whereas Christ is authority without power. After all, God "highly exalted him and gave him the name that is above every name" (Php 2:9) and Jesus "emptied himself" (Php 2:7). Is the relationship between the two one of complimentary emptiness? And if that's so, how does the Holy Spirit enter into the picture? Whatever "the spirit" does, it's confounded by the typical translation issues from Greek to English. The capitalisation of "Spirit" in most modern English translations doesn't help resolve the matter.
Unity does not mean equivalence. Paul's explicit differentiation should not be ignored.