If the bible records an account of someone doing something that we know to be an effective method at achieving some result and they get said desired result then it is evidence of the bible's scientific validity.
If the bible records an account of someone doing something known to be ineffective at achieving some result and they get it anyway (i.e. Jesus rubbing spit in the eyes of a blind person) then it's a miracle and is evidence of the existence of god and that the bible is the word of god.
If the bible makes a statement of fact that we know to be scientifically accurate (or, through some mental gymnastics, like the "circle of the earth" bit, can be made to seem scientifically accurate) then it is evidence of the bible's scientific validity and divine inspiration.
If the bible makes a statement of fact that we now know to be false then it was merely figurative language, metaphor or use of popular ideas of the day to make a point and is in no way evidence of the bible being scientifically invalid.