Some Good, Some Truth

2 Timothy 2:15
Be diligent to present yourself approved to God, a worker who does not need to be ashamed, rightly dividing the word of truth.

Do you think that if there is some good, then the whole is okay?

If a book has some truth, is the whole acceptable?

What are your thoughts upon this line of logic?

Can you be diligent, as described in 2 Timothy 2:15, and accept or endorse partial truth?

What do you think it means to rightly divide the word of truth?  Does that mean there is an un-right way to divide the word?