Why did God create life just for Earth? And not the other planets?

The universe is vast, perhaps infinite. Odds are, there is life somewhere else out there, and maybe there was long before us, and perhaps there will be again long after us, elsewhere and elsewhen. The universe is far greater than just the solar systems and galaxies we know. Life could exist, moreover intelligent life could exist (or could have existed, or may in the future exist) and they may have discovered their own religions and own ways to worship God. Maybe por some other vast, perhaps divinely orchestrated coincidence, they have discovered and named a religion exactly like Christianity. Maybe Christ - or a figure like him - lived and died on this planet as well.

The universe - and ergo, the possibilities - are quite literally infinite.

well think about all the sin on earth okay and life on another planet means the devil can still tempt them to sin so it seems like a waste of time to make extra terrestrial life if they would just be tempted to sin like us

who said there wasn't any life on other planets? life takes extremely exact conditions for life to form, so it's no surprise that there is a vast amount of o espaço in which there is no life, but who knows? there could be life on some planet far far away, the bible says nothing to disprove this :)

why does it matter if there are other lives on other planets, its not written that there aren't but the pergunta is why does it matter?

Well we don't really know that yet. Especially considering we've never even been out of the Solar System yet.

I mean, it is very likely that there is in fact life elsewhere in the universe. I think that it is impossible for there not to be.
I mean, we have found water on The Moon, Mars, lots of other planets moons, and even Mercury! One of Jupiter's moons Europa even has warmth water and oxygen.
Also life has been known to form in the most extreme conditions, from the coldest parts of Antarctica to even molten magma.

So, if God exists I doubt he made all of this o espaço just specifically for us. It would be kind of a waste of space.
But we simply just don't know yet. Hopefully we'll find other life out there sometime soon though.

Just remember, the universe is an unimaginably huge place.

How arrogant are we to think that it is only us or that other life forms have to breath oxygen, eat other animais or need water to survive. It matters because history shows us that we destroy what we don't understand or those that are different. I sometimes think God has given us so many chances to improve ourselves and we have failed to do that because of our sins, wickedness and eviL GOD has left us to our madness. Those that believe in him shall live on, but not here.