While all of JMB's suggestions are very much worth considering, I'd like to say also that the sentence as you have it is very well written and hard to improve upon. Keep in mind, please, that all of JMB's suggestions (as I am sure he will agree) are things to consider, not things to adopt because a good writer suggests them.
Next, "for the reader to be able to understand" is a clarification of "for the reader to understand." A good rule to keep in mind here is to say what you mean as concisely as possible. The goals of precision and conciseness are in opposition to one another and have to be balanced. So, if this addition of words clarifies your meaning enough to justify their inclusion in your mind, then include them. Otherwise leave them out. Again, though, it is important to consider them as JMB says. The words left out are part of what makes a great piece of writing.
Now, if you are going to change a shade of meaning ("deeper level" to "in more detail" would do that), you need to keep context in mind. Suppose, for example, you are reading Nietzsche and "the text" you reference is the simple but mysterious "God is dead". In this case, "deeper level" is probably the goal and "in more detail" probably isn't. (Of course, you probably aren't talking about Nietzsche either, but it makes for a good example.)
So, express yourself with precision, but don't get too wordy. Also, keep your context in mind.