Personal opinion:
First of all, the church is the key to the whole dream. Churches are generally sacred and solemn places, and you are guided by "God" to go to church. Church, God, these two details can show your inner yearning. You are a man of faith, at least in some ways.
Second, the church is very big and empty, and there is a detail behind it that you hide behind the piano. These two details show your inner loneliness and fear. A large and empty church can't hide behind the piano. The details of someone opening the church door highlight your inner feelings.
Third, there are ghosts, but they don't appear. You are guided by "God" to go to church, maybe you are avoiding the entanglement of non-existent ghosts. The reality of you may be entangled in some things recently, and you need to talk and comfort.
Fourth, gray face, snowy, cloudy, barefoot. Represents your inner disappointment and helplessness.
Five, there are two details that need to be analyzed by yourself in combination with the actual situation. There is also a red piano cover jumping from the window. Most people wake up naturally when they dream of falling from a height, but you won't; You've always remembered the red harp cloth. Maybe you have seen red piano cloth in reality, or it may be a metaphor.