How did life begin in the universe?

Q: How did life begin in the universe? How did non-living things/atoms/particles give birth to life (a living, walking, speaking, thinking human)?
Krishna: Just simple chemicals and electromagnetic radiation. Magic? No, science!

Atoms interact to form molecules and molecules interact to form large systems and structures. Living cells are made of specialized molecules.They are responsible for all the biological processes like metabolic pathways.    These are powered by chemical reactions.

Scientists have seen Coenzyme A  arising from non-living substances by use of a certain wavelength of the sunlight. DNA assembly is facilitated by electromagnetic signature of real DNA that was scanned in a distant location. 
Some of the complex chemicals necessary for life's existence were also found in meteorites fallen to earth. So simple chemicals with the help of electromagnetic radiation can go from non-living to living - Anywhere in the universe under the right conditions. 

So life emerged from non-living chemistry. When molecules are left with an energy source, they interact with one another often forming very complex molecules necessary for life.They can self assemble into membranes, DNA or RNA and other structures too.
In biology, abiogenesis (from a-‘not’ + Greek bios ‘life’ + genesis 'origin') or the origin of life is the natural process by which life has arisen from non-living matter, such as simple organic compounds. The prevailing scientific hypothesis is that the transition from non-living to living entities was not a single event, but an evolutionary process of increasing complexity that involved the formation of a habitable planet, the prebiotic synthesis of organic molecules, molecular self-replication, self-assembly, autocatalysis, and the emergence of cell membranes. Many proposals have been made for different stages of the process (4).

Abiogenesis

The study of abiogenesis aims to determine how pre-life chemical reactions gave rise to life under conditions strikingly different from those on Earth today. It primarily uses tools from biology and chemistry, with more recent approaches attempting a synthesis of many sciences. Life functions through the specialized chemistry of carbon and water, and builds largely upon four key families of chemicals: lipids for cell membranes, carbohydrates such as sugars, amino acids for protein metabolism, and nucleic acids DNA and RNA for the mechanisms of heredity.

Any successful theory of abiogenesis must explain the origins and interactions of these classes of molecules. Many approaches to abiogenesis investigate how self-replicating molecules, or their components, came into existence. Researchers generally think that current life descends from an RNA world, although other self-replicating molecules may have preceded RNA.

The classic 1952 Miller–Urey experiment demonstrated that most amino acids, the chemical constituents of proteins, can be synthesized from inorganic compounds under conditions intended to replicate those of the early Earth. External sources of energy may have triggered these reactions, including lightning, radiation, atmospheric entries of micro-meteorites and implosion of bubbles in sea and ocean waves. Other approaches ("metabolism-first" hypotheses) focus on understanding how catalysis in chemical systems on the early Earth might have provided the precursor molecules necessary for self-replication.

These are the key points: The Earth formed roughly 4.54, point, 5 billion years ago, and life probably began between 3.53, point, 5 and 3.93, point, 9 billion years ago.The Oparin-Haldane hypothesis suggests that life arose gradually from inorganic molecules, with “building blocks” like amino acids forming first and then combining to make complex polymers. In the 1920s, Russian scientist Aleksandr Oparin and English scientist J. B. S. Haldane both separately proposed what's now called the Oparin-Haldane hypothesis: that life on Earth could have arisen step-by-step from non-living matter through a process of “gradual chemical evolution.(5)” Simple inorganic molecules could have reacted (with energy from lightning or the sun) to form building blocks like amino acids and nucleotides, which could have accumulated in the oceans, making a "primordial soup."The building blocks could have combined in further reactions, forming larger, more complex molecules (polymers) like proteins and nucleic acids, perhaps in pools at the water's edge.The polymers could have assembled into units or structures that were capable of sustaining and replicating themselves. Oparin thought these might have been “colonies” of proteins clustered together to carry out metabolism, while Haldane suggested that macromolecules became enclosed in membranes to make cell-like structures(6,7).

The Miller-Urey experiment provided the first evidence that organic molecules needed for life could be formed from inorganic components. In 1953, Stanley Miller and Harold Urey did an experiment to test Oparin and Haldane’s ideas. They found that organic molecules could be spontaneously produced under reducing conditions thought to resemble those of early Earth. Some scientists support the RNA world hypothesis, which suggests that the first life was self-replicating RNA. Others favour the metabolism-first hypothesis, placing metabolic networks before DNA or RNA.
Scientists now think that the atmosphere of early Earth was different than in Miller and Urey's setup (that is, not reducing, and not rich in ammonia and methane) art superscript,  comma, end superscript. So, it's doubtful that Miller and Urey did an accurate simulation of conditions on early Earth. However, a variety of experiments done in the years since have shown that organic building blocks (especially amino acids) can form from inorganic precursors under a fairly wide range of conditions(8).

Recent research has also shown that reactions of alpha-hydroxy acids, similar to the alpha-amino acids that make up modern proteins, form large polymers easily under conditions presumed prevalent on early Earth. These alpha-hydroxy acid polymers may have aided in the formation of living systems on early Earth (1).
 Scientists  have discovered recently a new set of chemical reactions that use cyanide, ammonia and carbon dioxide -- all thought to be common on the early earth -- to generate amino acids and nucleic acids, the building blocks of proteins and DNA (2).
They showed how cyanide can enable the chemical reactions that turn prebiotic molecules and water into basic organic compounds required for life. Unlike previously proposed reactions, this one worked at room temperature and in a wide pH range. The researchers wondered whether, under the same conditions, there was a way to generate amino acids, more complex molecules that compose proteins in all known living cells(3).
They suspected that cyanide, even without enzymes, might also help turn α-keto acids into amino acids. Because they knew nitrogen would be required in some form, they added ammonia -- a form of nitrogen that would have been present on the early earth. Then, through trial and error, they discovered a third key ingredient: carbon dioxide. With this mixture, they quickly started seeing amino acids form.
These are very simple reactions. Because the new reaction is relatively similar to what occurs today inside cells -- except for being driven by cyanide instead of a protein -- it seems more likely to be the source of early life, rather than drastically different reactions, the scientists think. The research also helps bring together two sides of a long-standing debate about the importance of carbon dioxide to early life, concluding that carbon dioxide was key, but only in combination with other molecules.
In the process of studying their chemical soup, the researchers discovered that a byproduct of the same reaction is orotate, a precursor to nucleotides that make up DNA and RNA. This suggests that the same primordial soup, under the right conditions, could have given rise to a large number of the molecules that are required for the key elements of life.

At this point of time these are all only educated guess works. 

After simple life forms emerged from non-living matter, they evolved into complex organisms with more complex bio-chemistry till they reached the pinnacle of human being origin.