Which is the opposite of death - life, or birth?

depends from your point of view. I'll explain:

1. If you don't believe in any form of afterlife and etc, for you death is a state, and thus life is it's opposite.

2. If you do believe in afterlife of any sort, death is a transition, an event that changes state, and thus birth (an other event that changes state) is the correct opposite.

Since death is the end of life....

Birth is the beginning of life. Thus the opposite.

birth

Death as a verb would be the opposite of birth

Death as a noun would be the opposite of life

birth

i don't think its a difference as far as the thesaurus or american english is concerned but i like life better. to me a birth does not mean in motion but death absolutely means not in motion to me birth denotes a past tense & death is a description

It depends.

Are you referring to the condition of death or the process of death?

If the former, then life... If the latter, then birth.

birth-

life implies that one has a choice to "no die" indefinately.

death is the end state of birth for all things.

I'd have to say birth.

There are no "opposites" here. You are born. You live. You die. It's a continuum.