Without birth and death, and without the perpetual transmutation of all the forms of life, the world would be static, rhythm-less, undancing, mummified.
It's prudent to gain the whole world and lose your own soul. But don't forget that your soul sticks to you if you stick to it; but the world has a way of slipping through your fingers.
And then he drew a dial from his poke, And looking with lack-lustre eye, Says very wisely, 'It is ten o'clock: Thus we may see', Quoth he, 'how the world wags: 'Tis but an hour ago since it was nine, And after one hour more 'twill be eleven; And so from hour to hour we ripe and ripe, And then from hour to hour we rot and rot.