What is Krishna Consciousness?

Krishna Consciousness is not a question of belief, it is a science.
The first step is to know the difference between a living body and a dead body. What is the difference? The difference is that when someone dies, the spirit soul or the living force leaves the body. And, therefore, the body is called “dead.” So there are two things: one is this body; and the other, the living force within the body.
One must first understand that he is a soul, or something other than this body.For example, as a child grows, he becomes a boy, the boy becomes a young man, the young man becomes an adult, and the adult becomes an old man. Throughout all this time, although his body is changing from a child to an old man, he still feels himself to be the same person, with the  same identity.  The body is changing  but  the  occupier  of the  body, i.e. the  soul, is remaining the same.

So when your body is finished, annihilated,  you are not finished. You get another  body, just as you may change your coat and shirt. If you come to see me tomorrow wearing a different shirt and a different coat, does that mean that you are a different person?

No. Similarly, each time you die, you change your bodies but you, the spirit soul within  the body, remain the same. This point has to be understood.  Then, one can make further progress in the science of Krishna Consciousness.
The spirit soul is invisible to our material eyes. It is atomic in size. After the destruction  of the gross body, which is made up of the senses, blood, bone, fat, and so forth, the subtle body of mind, intelligence and ego goes on working. So at the time of death, this subtle body carries the small spirit soul to another gross body.
The process  is just  like air carrying  fragrance.  Nobody  can see where  this  rose fragrance is coming from but we know that it is being carried by air. You cannot  see how but it is being done.  Similarly, the  process  of transmigration   of the  soul  is very subtle.  According  to  the condition  of the mind at the time of death, the minute  spirit soul enters  into the womb of a particular mother through  the semen of a father and then the soul develops a particular type of body given by the mother. It may be a human being; it may be a cat, a dog or anything.

You are  eternal.  According  to  your  work,  you  are  simply  changing  bodies.  Therefore,  you should want to know how to stop this business, how you can remain in your original, spiritual body. This is Krishna Consciousness.