There were some religious overtones as well. There was a prophesy which there is in many movies. Then at a key point in the movie the prophesy is revealed to be made up. The Gandalf/ Dumbledore character admits it. Then they try and take it in a Dumbo direction. That is if you just believe you can do something you can. Get rid of the crutch like a feather or a prophesy and just do it yourself. The difference is that in the Dumbo story there is good reason to believe Dumbo can fly with or without the feather. Here there is no reason to be believe the characters can do what they are attempting. So they are choosing to believe in belief. The power of positive thinking. Tells yourself you can do it and you will do it.
The trouble is it isn't true. We are more powerful when we believe in ourselves. Yet we are still finite and fallible. We can make mistakes. We can face challenges that are just too big for us. How can we put that reality out of our mind? Humans are lovers of truth. We are just incapable of full embracing something that we know to be false.
People think of religion that way. It is just believing in something good and that is, in itself, something good. People even go so far as to say it does not matter if it is true. Its power is in the way believing it changes us and not in its truth.
Atheists totally reject that. If it is not true then we should not make any pretense that it is true. We should just say out loud it is false. Many parts might still be salvageable but the central story is false.
Liberal Christianity tries to make it work. They accept Christianity as true but not really. It is like a piece of art can be true but not in a factual sense. The trouble is when faith comes under stress. When we have to sacrifice for our faith. When we have to face the possibility of failure. Then they give themselves an out. Faith is there to help us so the minute it stops helping us we can go into atheist mode.
Are we guaranteed success? Yes and No. Look at the martyrs. St Maximilian Kolbe was very confident God would help him fight the Nazis. Yet he was taken to a concentration camp and died there. That was success. That is the key. Not to know that God will make us win the battle in worldly terms. We don't know that. What we do know is that God will give us a victory on His terms. It might involve suffering and death. If that is the road God wants us to travel we need to be prepared to travel it well. St Maximilian Kolbe was not less successful than Bl Teresa of Calcutta. They both fought battles and in worldly terms one won and one lost. In spiritual terms both won.