A. These are important questions and you are wise to seek answers to be sure you are functioning within the guidelines of the copyright law.
Copyright length is currently the author's lifetime plus 70 years. This time period applies to books, as well as music. Even if it's in public domain and can be used without permission, you still have to give credit. Note that this length changes when there are co-authors. For exceptions to this rule, go to www.copyright.gov for specifics.
If you are not familiar with the term public domain, it means that the written material either was never copyrighted, or that the copyright has expired; and you are free to use it without permission as long as you give credit.
The only translation of the Bible that is already in public domain is the King James Version. You can quote from it without having to worry whether or not you need to ask permission. Be sure you always identify the version with a Bible reference, such as John 3:16 KJV.
As far as other versions of the Bible are concerned, they are all protected much the same as any other published book. However, guidelines for quoting are somewhat different. Most versions have a blanket agreement with book publishers that they can quote up to 250 or 500 verses without having to ask permission, as long as the quoted portion does not include a certain number of consecutive verses or a complete book of the Bible. Periodicals have a similar agreement.
In all cases it is critical that the quote is rendered exactly as written in that version, and proper credit is given. Houses that publish Bibles provide more specific guidelines on their Websites for using quotes.