What is faith?

What is faith? Is it blind belief? Or is it the result of logical reasoning? For a mature person it must be the end product of contemplation, evaluation and perhaps even experimentation..Just as a beautiful sculpture shows itself from out of a shapeless mass  of rock at the tip of a chisel wielded by a brilliant artist, faith is the final product of a lot of processing. Faith may be beneficial  or detrimental  depending on  the quality of the mind which nurtures it .