Life is not an assemblage of mollecules, cells, tissues, organs and functions. In fact, cells, tissues and organs could be dead or alive, telling you that life is not something we quite fully understand to start with.
It depends on how you want to define life, I quite like the Biological requirements for something to be defined as life:
Homeostasis: Regulation of the internal environment to maintain a constant state; for example, electrolyte concentration or sweating to reduce temperature.
Organization: Being structurally composed of one or more cells, which are the basic units of life.
Metabolism: Transformation of energy by converting chemicals and energy into cellular components (anabolism) and decomposing organic matter (catabolism). Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life.
Growth: Maintenance of a higher rate of anabolism than catabolism. A growing organism increases in size in all of its parts, rather than simply accumulating matter.
Adaptation: The ability to change over a period of time in response to the environment. This ability is fundamental to the process of evolution and is determined by the organism's heredity as well as the composition of metabolized substances, and external factors present.
Response to stimuli: A response can take many forms, from the contraction of a unicellular organism to external chemicals, to complex reactions involving all the senses of multicellular organisms. A response is often expressed by motion, for example, the leaves of a plant turning toward the sun (phototropism) and by chemotaxis.
Reproduction: The ability to produce new individual organisms, either asexually from a single parent organism, or sexually from two parent organisms.
(just copied from wiki)
Life is the manner in which cells are constructed and the molecular pathways which occur to maintain, replicate etc the cell.
Live cells and dead cells may look the same (if you nuke them with formaldehyde!). But if you look at the biochemistry within the cell, they are nowhere near the same.
Consciousness is something we'd have a harder time explaining, but, that isn't required for life.
I don't know if there is life out there, but I'd say it's a probability. Something else to take into account, the vast timescales of the galaxy, some forms of life could have come into existence and perished before life developed on life, life could develop on other planets long after life on earth is extinguished.