The biblical canon as we know it today emerged over a process of many centuries. There was not a single moment at which the church decreed what books would constitute scripture. Instead, starting in the 4th century, we have evidence of the opinions of individuals or of regional church councils about what books should be read in worship, but these lists differ somewhat. 

Understanding the process of canonization helps us to see that there wasn’t a moment when books were included or removed from the canon.

There were lots of religious and spiritual writings that were important to Jewish and Christian believers. Not all of these were included in the canon. This does not mean that they were deemed heretical. In fact, many of the noncanonical works were valued as expressions of the faith. They were edifying to read, but not part of “Scripture”—that is, they weren’t the books that you read from when you gathered for worship. There are LOTS of these works, spanning many centuries. What we now call the Old Testament Pseudephigrapha, the New Testament Apocrypha, and the Nag Hammadi LIbrary are large collections of works that fall in this category. The Apocryphal books of the Bible, which are counted as Scripture by Catholics but not Protestants, might also be considered as an answer to your question, depending on your perspective. One website with links to a number of early Christian writings is http://www.earlychristianwritings.com.