My attempt.
我们内心是否平和在很大程度上是由我们是否能生活在现实之中所决定的。
To a great extent, whether we are able to be in peace or not is up to whether we are able to live in the reality or not.
我们内心是否平和在很大程度上是由我们是否能生活在现实之中所决定的。
To a great extent, whether we are able to be in peace or not is up to whether we are able to live in the reality or not.