Figure out before getting book with solution (7)
I believe the answer is:
solvent
'solution' is the definition.
'figure out before getting book' is the wordplay.
'figure out' becomes 'solve' (synonyms).
'before getting' is a charade indicator (letters next to each other).
'book' becomes 'nt' (New Testament).
'solve'+'nt'='SOLVENT'
'with' is the link.
(Other definitions for solvent that I've seen before include "In a position to pay one's debts" , "something that may be abused?" , "Having assets in excess of liabilities" , "not bust" , "Possessing enough money to meet commitments" .)