I think grammar is one of ingredients. BUT if we don't have ingredients, how can we cook delicious food ?  

Speaking is definitely more important than grammar. The entire point of language and communication is to get the point across to the audience. Many people overlook this obvious fact and hold themselves back from speaking until they have perfect grammar. Some people are scared and even feel ashamed of themselves when they make grammatical mistakes in speech - all the while the listener understands the speaker perfectly. All of this is not necessary if the listener can understand the speaker (which is the sole objective in communication!).

I've read a very good analogy on a language learning forum. It says that languages are comparable to car engines (engine = language, engine pieces = grammar and individual words). It would be much easier and far more time-efficient for one to put together a car engine if one first takes apart an assembled one (ie, knows what the engine looks like); as opposed to if one started with all the engine parts from scratch with no clue what the final product looks like.

It's not that grammar is not important, just that grammar should never hinder a learner from attempting to speak. Sorry for my disorganised thoughts.

What about for adults? They have already learned english to their language or their laguage to english. I know one of the problems is to traslate A to B, B to A. 

Think about children, how they learn the language.  They don't know how to read, therefore they don't study the grammar rules, and yet they learn to speak the language fast and fluent.  Best to study English through listening and conversation practice first, then grammar later when you are in the advanced level.

I think speaking is more important. The more you speak the more you remember. Gestures and feelings help to remember words. When you are constantly expose through "real language" or standard; you will learn faster than through boring grammar and unhelpful words.