You must have seen it happen many times. Sometimes a butterfly enters into a room. She knows she has entered by the door; she knows there is an entry, so she knows tacitly that by the same door she can go out. But then she starts moving to the window, goes on struggling with the glass. And the more she struggles with the closed window, the more nervous she becomes. The more nervous she becomes, the more unconscious, afraid of death, afraid of being always caught in this room forever. She loses consciousness! In that unconscious state she starts fighting more, even with the walls. And the door is there! And the door has been there. And she knows tacitly. How can she forget? It seems a miracle. She has come by the door. Why does she not get out by it?
The same door that brings you into the world takes you out of it. Remember, it is the same door! On one side is written 'Entrance', on the other side is written 'Exit'. It is the SAME door. These are two sides of the same door. Passion brings you into the world, passion takes you out of it. Desire brings you into the world, desire takes you out of it. Greed brings you into the world, greed takes you out of it. Never fight! The lower is not only the entrance, the lower is the exit too.
This is something to be understood. Let it sink in your heart Never fight! Never create any conflict! Otherwise you will create anguish, otherwise you will become more miserable. That's what has happened to you. People are miserable just like the butterfly. Listen to this story:

Zen Master, Shen Tsan, gained his enlightenment through Pai Chang. He then returned to the monastery in which he had been ordained by his 'first teacher', the monk who had brought him up from childhood and who, at that time, was a very old man....

Remember: he was just a teacher, not a Master. So Shen Tsan had not achieved his enlightenment through him. He had to go to some other Master, to Pai Chang. When he attained enlightenment he came back to his old teacher. He was a compassionate man, a kind man. He had brought up Shen Tsan from his very childhood. He was almost like a father.

One day Shen Tsan was helping his old teacher to bathe. While washing the old man's back, he said to him, "This is such a fine temple, but the Buddha in it is not at all holy!" His old teacher then turned round and looked at him, whereupon Shen Tsan commented, "THOUGH THE BUDDHA IS NOT HOLY, HE CAN STILL RADIATE THE LIGHT."

The old man felt a little embarrassed, but he didn't say anything. This was absolutely new: "This young man has got something new now since he has come back. His quality has changed. And sometimes he utters statements which can mean much, which may not mean anything. He may have just learned them somewhere. Or, who knows whether he has had some insight, some satori?" The old man watched and waited.

Again, one day, while the old man was reading a sutra near a paper-covered window, a bee tried desperately, with all its strength, to fly out of the room through the paper but was unable to get through.
Shen Tsan, seeing this. said, "The world is so vast and wide that you may easily set yourself free in it. Why, then, do you foolishly bore into the old, rotten paper?"

Now, this is very meaningful. It has two meanings. The old man is reading his old book, and the bee is trying to get out by the paper-covered window -- in Japan they make paper curtains. And Shen Tsan says, "The world is so vast and wide that you may easily set yourself free in it. Why, then, do you foolishly bore into the old, rotten paper?" And he sang a GATHA:

"While the empty door is open wide
How foolish is to try to get out
By thrusting against the window!
Alas! How can you
Raise your head above the slough
By putting your nose against the old, rotten paper
For a hundred years?"

And the old man is getting to be nearabout a hundred years old. Now this is too much.
Hearing this remark, the old man laid down his book and said to Shen Tsan, "For quite a few times now, you have made unusual remarks. From whom did you gain your knowledge while you were away from home?"
Shen Tsan replied, "I have reached the state of peaceful rest through the grace of Master Pai Chang. Now I have come back home to pay my debt of gratitude to you."
The old teacher then prepared a great festival in his young disciple's honour, summoned the monks in the monastery to the assembly hall, and besought Shen Tsan to preach the dharma to all. Whereupon Shen Tsan ascended to the high seat, and, following the tradition of Pai Chang, preached as follows:

"Singularly radiating is the wondrous
Light Free from the bondage of matter and the senses.
Not binding by words and letters
The Essence is nakedly exposed in its pure eternity.
Never defiled is the Mind-nature;
It exists in perfection from the very beginning.
By merely casting away your delusions
The Suchness of Buddhahood is realized."

Listening to these words, seeing his own disciple illumined, feeling for the first time who he had become, the old man touched the feet of his own disciple. And when he was bowing down and touching the feet of his own disciple, he became enlightened, the insight opened.