Two Verses

[bobby1933]

For this  reason was man created alone, to teach thee that whoever destroys a single soul....scripture imputes (guilt) to him as though he had destroyed a complete world, and whoever preserves a single soul....scripture ascribes (merit) to him as though he had preserved a complete world. -- Talmud, Sanhedrin 37a.

If anyone murders an (innocent) person it is as if he had murdered the whole of humanity and if anyone saves a person it is as if he  had saved the whole of humanity. -- Quran 5:32.

So save humanity, preserve the world.