First of all, reading widens your mental (what many call intellectual) horizons. The more you read, the more information you pick up about the world and everything in it. This leads to a solid core of knowledge that is useful to you in a wide variety of real-life situations.
Secondly, reading expands your word power or your store of vocabulary. And having more words at your command means greater ability to deal with and express more thoughts and clearer ideas. This enhanced ability greatly augments your chances of success in your field of work. No other activity builds your vocabulary and comprehension skills as effectively as reading.
Thirdly, reading shows you how different writers present their thoughts, facts, logic, emotions, arguments, humour, etc., which, if you imbibe their techniques, will hone your own writing skills. Moreover, when you read important and serious works in different spheres of knowledge, you gain skills in dealing with complex ideas.
Fourthly, research shows that avid readers can comprehend others’ situations and attitude better. If you are a voracious reader, you acquire the ability to separate essential from nonessential information. Also, you can often see how apparently unrelated ideas and facts are connected. As a result, you tend to be more flexible in your thinking and more open to new ideas. You develop or sharpen the ability to understand how other people think and feel, react positively to change and deal with various situations better.
Finally, reading is enjoyable. It can provide you with enormous satisfaction and pleasure, and, not infrequently, a happy escape from harsh realities of life.
In sum, reading helps you live a rich, meaningful and happy life.