Called by human names, we always existed

>! So we are looking for the human names for something that has existed before humans.

We are like sinful dwarves, or wonders that glisten.

>! There were *seven dwarves* in the tale of *Snow White* (I figured this out) and @AHKieran has figured out that the line also mentions *sins* (of which there are said to be 7), and *wonders* (7 wonders of the world). Also there are 7 further lines after this one. So the answers are things that belong to a set of 7.

They could be:
>! The 7 classical planets ("planets" of our solar system which can be seen with the naked eye, including our two luminaries the sun and moon)  
>!  
>! One of us is there to listen. JUPITER (known for its eerie sounds)  
>! One of us is there to cook. MERCURY (the element Mercury is used in thermometers, which in turn can used in cooking)  
>! Another, at night, is there to look. MOON (the nighttime luminary, some say it has a face)  
>! One is the leader to show the way. VENUS (appears in the night sky usually before the stars do)  
>! One does what is done by day. SUN (the daytime luminary)  
>! One is there to look into life. MARS (scientists have searched for life on Mars)  
>! Another carefully cuts like a knife. SATURN (the only one left - has blade-like rings)  

Alternatively:

>! other things I rejected that come in a group of 7 and existed before humans named them:  
>!  
>! - days of the week  
>! - continents  
>! - seas  
>! - colours of the spectrum