We should know how much creative force God has, wonderful. So out of that wonderful creative force, we living entities, we have got a little particle, and therefore we can manufacture these wonderful machines, and we are struck with wonder, "Oh, we have done so great thing." No. We should try to understand still further, still further.
So the Śrīmad-Bhāgavata says that if you want to be free . . . free means just like you are trying to go to the moon planet by so many mechanical arrangements, but if you are free spiritually, then you can go any planet you like, immediately. The yogīs, those who are perfect yogīs—not these nonsense yogīs—those who are perfect yogīs, they can go at their will any planet they like. That is yogic perfection. When a yogī becomes perfect, he dies . . . he does not die. "Die," this word is not actually applicable.
When he leaves this body . . . actually, nobody will die. We simply quit this body and accept another body. We are forced by the laws of nature according to karma. By practice of yoga system we can avoid the forcible nature's law, but we can leave this body according to our sweet will, not being forced by the nature's law. Just like Bhīṣmadeva. Bhīṣmadeva, he knew this yoga practice. Therefore he was not to be killed. Unless he desired to die, nobody could kill him.
So yogīs . . . still there are many yogīs in India, they are living for seven hundred years, or three hundred years, four hundred years. They consider not yet perfect. Not yet perfect. They are trying to make perfection of the yoga practice, and they look like young men, say, twenty-five years, thirty years old. But they are seven hundred years old, three hundred years old. There are still yogīs. They are yogīs. They have practiced yoga. Still they consider they are not perfect. The perfection will be when a yogī at his sweet will can leave this body and can go any planet he likes. Not only within this material universe, but also even, if he likes, he can go to the spiritual planet also. That is yoga.