Science shows us that the universe evolved by self-organisation of matter towards more and more complex structures. In the process of biological evolution from bacteria-like tiny cells to all life on earth, including us humans, complex life forms arose from simpler ones. Science teaches us that life spontaneously occured from the synthesis of simple organic molecules. whether this was designed or not, I don’t know.
Amino acids and proteins are essential building blocks for life. They can be made from methane, water, hydrogen and ammonia. These are said to be the components of the “prebiotic soup”, the broth of starting materials from which life was created. We can makes these in the lab so it’s not unreasonable to think that this could have happened in nature if the conditions were right.
DNA is also required for life. But it is thought that this could be too complex to have spontaneously formed! So there must have been an organism that created it!
For this is have happened, the first cell must have been formed. A cell is a membrane-bound unit that contains organelles. Cell membranes are held together by the oil-water repelling each other forces. It’s the same force that if you pour droplets of oil into water, they float on the surface, they don’t mix with the water. This is a natural property so you can imagine this happening spontaneously too.