影片回闪的童年时间线与水之影像正是雷查尔斯对弟弟乔治之死的愧疚与对母亲的承诺，这些就是他坚持的源头，他就是背负着这些承诺与愧疚，勇往直前的进行他的音乐之路，救赎后的惊艳一生。

It is the reason why he insisted on his music life, his guilt about the death of his brother,Gorge, and the promise to his mother, which flash in the film with the time clue of childhood and the vision of the water.And with the sufferings of the guilt and promise, he marched on bravely with his music dream and achieved a brilliant reborn existence finally.

解释一下，

其中，由于成分太长，我把it 指代的 his guilt about the death of his brother,Gorge, and the promise to her mother 丢到句子后面。而且把它看成一个抽象整体，代表“源头”或者“原因”。

existence则是life同义词，免得重复。

a brilliant reborn existence 中的brilliant 和 reborn 都是修饰existence的形容词。

文章比较文学化，好像是影视评论，所以翻译时在结构上，形式上我变化比较大些。希望能帮到你。呵呵