The other side asserts Jesus is not God, but a bare assertion doesn't shift the posterior much. A useful test is this: imagine first-century Jewish monotheists who prayed to, worshiped, and called a crucified man Lord. Paul's letters, our earliest sources, already do this in Philippians 2 and 1 Corinthians 8:6, and the Aramaic maranatha prayer likely predates him. That's a costly practice within strict monotheism. The simplest explanation is that they genuinely placed Jesus on God's side of the line. I'd put maybe 80 percent confidence there, not certainty.