The story of Noah in the Bible is relatively sparse. Noah never says anything. God does all the talking. In the movie, well, God may be doing some communicating, but since the narrative is told more from the ground, from Noah and his family’s perspective, Noah is the main character, making choices.
Making choices. I think that’s an important thing to highlight. One of the strange ironies of religious life, it seems, is that the closer we get to our God, whomever that may be, the seemingly fewer choices we get–until we are the Hand of God, the Feet of God, the Puppet of God. I don’t think this is really the case. But depiction in movies and books sometimes have us think characters who are devoted to their god cease to think and act based completely on the commands of God. One should add “the interpretation of what they believe to be” between “on” and “the” in that last sentence. Because in many cases, believers have to do a lot of interpreting.
The movie holds out that question to answer. Certainly Noah has to decide HOW he is hearing God. He gets parts right—there is going to be a flood. God wants him to build an ark. The animals are going to come and get on board the boat. After that, though, Noah is subject to some speculation and extrapolation when he can’t really hear a clear answer from God.