Can I take a statement from vol a of the encyclopedia Britannia and prove something said in vol c of the same encyclopedia?
an encyclopedia is very different from the bible. I know you don't believe it, but it is.
an encyclopedia is a book of facts, researched and presented as facts (not as a story).
An encyclopedia starts "Aa - aardvark" and carries on through to "Z - zebra" (more or less) listing dry, unbiased facts and theories.
If, for example, one page on condoms describes what they do and how they do it (prevent pregnancy and the spread of STD's) and another page says (on the history of some African country, for example) that after the introduction of the condom program, unwanted pregnancies fell, as did the rate of STD transfer, you can probably surmise for yourself what did it.
If the bible, on the other hand, says in one book "jesus walked on water to the fisherfolk" and in another book says "it said in the scrolls of hooplah that my mate jesus walked on water to the fisherfolk", that is not the same thing - here the bible is referring to itself (it's a made up but valid type-example).
If the bible repeats itself that a certain city was destroyed, that also doesn't prove it really happened.
Maybe you believe the bible to be of the same authenticity as an encyclopedia...but the latter has pictures and drawings from real life.
Older books corroborate with other books written by other, unconnected peoples.
the bible? It corroborates primarily and singly with itself.