Reading and Writing are Complimentary to Each Other
I am of the view on the experiential basis that you can be a good reader if you can write down whatsoever you have read.
I state another claim on the benefit of writing. I believe that it is a hidden secret of spiritual life. If you try to write about the thoughts which come to your mind, you are virtually exploring the actual nature of the truth; the truth of the purpose of living this life; the reality of the motive of getting this life and the truth is pure.
For me, reading and writing are complementary to each other. You cannot merely read. There is no benefit in only reading. One may say that it is one of the means of entertainment. There is no entertainment in writing, and one can present it as a counter.
Well, it is a mere opinion. When one reads, and there is good stuff in the discourse which you read, then it is bound to leave an impact on your psyche and ultimately on the personality. However, there is a danger of becoming a fanatic if you remain confined to reading. Someone and in reading the author of the discourse starts possessing your mind. You do not continue your normal being. It generally happens in case of the holy books and the reader does not read such books on his own. The reader listens to an interpreter of such books and memorizes many portions of the book. Such readers generally claim that there is no benefit from reading books. But it is for them a message that there are two books which have ruled the world and those two books will continue to dominate humanity for times to come. Those two books are the Bible and the Quran. There are many similar books. The reading of books continues even by the illiterate people. The only difference is that an illiterate cannot read a book but listens to the book. Therefore, there is a claim that there is a lesser benefit of reading a book.
The writing makes a lot of difference to the reading. While writing, one tends to reflect on the content of the material of the book which one has read. The book is left aside. The author of the book is debarred from directing your attention and flow of thought. It is you and your thoughts which are the topic for execution. You have read a book. The discourse has left a trace on your mind. While writing, you try to explore the trail of the content you have read. It is a different phenomenon which is at play. You are in a reflecting mode. Your originality and intrinsic abilities are at play. You pour out your thoughts which is a work of creation. You may be recollecting the facts which you have acquired from thinking. But while doing so, you are performing a mystic activity. You are giving linguistic expression to the thoughts which exist in a realm which the psychologists and neuroscientist have yet to discover. That unknown mystic wonder is at play when you write.
Reading is an exercise. So is the writing. When they are carried out in synchronization, it makes the mind healthy and life vibrant.