Reading a lot will among others increase your knowledge of vocabulary and culture. However, it is very difficult to actually learn how to speak by just reading a language. Even if you know how to read phonetic transcriptions, you're bound to make mistakes if you don't actually practice the language and speak it with others. Learning a language and learning how to use it well is complicated and takes a lot of time and practice.
So:
Yes, reading will help you improve your skill in and knowledge of a language.
No, it will not help you speak a language perfectly. For that you will really need to practice by speaking it yourself and listening to others. So combine reading with listening and speaking. This may even be listening to audio fragments or the radio etc and then repeating what has been said.