Lichens are composed of two organisms living beneficially together and forming a new life form.  The dominant partner in the relationship is a fungus.  Fungi, of themselves, are incapable of making their own food and survive by being parasites and decomposers.  The lichen fungi cultivate partners that manufacture food by photosynthesis, such as algae (Kingdom Protista) and cyanobacteria (Kingdom Monera), formerly called blue-green algae.  The relationship is symbiotic, with both organisms benefiting from the arrangement. 

The fungi part breaks down rock, wood, and other organic matter to provide minerals and nutrients to the relationship.  The algae part has chlorophyll and is able to supply the relationship with energy through photosynthesis.  Thus, by living together, they can utilize a wide variety of habitats in which, alone, they could not survive, such as deserts and the Arctic.  In many cases, a lichen’s fungi and algae can be found living in nature separately, but many lichens consist of fungi that have become dependant on their algae partner and cannot survive on their own. 

Growing in spots that are too harsh or limited for most other organisms—such as bare rock, desert sand, cleared soil, dead wood, animal bones, and living bark—lichens can survive extremes of heat, cold, and drought and are able to shut down metabolically during these periods of unfavorable conditions.  One species, the vagrant lichen, is even mobile, moving from place to place by the wind.  Lichens can colonize almost any undisturbed surface if given appropriate amounts of light and moisture, clean air, and lack of competition.  It is estimated that lichens are the dominant vegetation on eight percent of the earth’s terrestrial surface. 

Lichens are highly diverse in looks, varying from gray and green rosettes on trees, green to orange crusts on rocks, tangled brown to green hair hanging from branches, to tiny green goblets on the ground.  They are very slow growers, often growing less than a millimeter per year, and are believed to be among the oldest living things on earth.

Lichens produce an arsenal of more than 500 unique biochemical compounds that serve to control light exposure, repel herbivores, kill attacking microbes, and discourage competition from plants.  Among these are many pigments and antibiotics that are very useful to man.  Half of all lichen species have antibiotic properties.  Worldwide, lichens have been used for making dyes, medicines, poisons, clothes, soups, jellies, breads, and fine perfumes.  Lichens with cyanobacteria contribute to soil fertility in a major way by taking nitrogen gas from the air and turning it into biologically usable compounds.  Lichens are also valuable as food and nesting material for a multitude of wildlife, from the tiny hummingbird that camouflages its nest with it to the large caribous of the far north, which depend on it for food during the long winters.

Just as lichens are composed of two organisms living together and forming a new life form, so the person who cultivates a relationship with Christ and unites his or her life with Him becomes a new creature.  “Therefore if any man [be] in Christ, [he is] a new creature: old things are passed away; behold, all things are become new.”  11 Corinthians 5:17.  “Our life is to be bound up with the life of Christ; we are to draw constantly from Him, partaking of Him, the living Bread that came down from heaven, drawing from a fountain ever fresh, ever giving forth its abundant treasures.”  Christ’s Object Lessons, 129.  “The Christian’s life is not a modification or improvement of the old, but a transformation of nature.  There is a death to self and sin, and a new life altogether.”  The Desire of Ages, 172.