Just read a 12 page pdf entitled, How Did We Get Our Bible and Has It Been Changed? by Dr. Matthew S. Harmon.
While the report is brief, it is very informative and persuasive. Here's his conclusion that the paper fleshes out in more detail:
"In closing I want to leave you with two bottom-line conclusions to walk away with today.
First, the Bible that we holding our hands contains the books that God intends for us to recognize as authoritative for faith and practice. You have no need to fear that some vast conspiracy has managed to prevent us from having documents that are inspired by God for the benefit of his people the church. The reason books like the Gospel of Thomas or the Gospel of Judas are not included in the Bible is because there was widespread recognition in the church from a very early period that documents such as these did not conform to the rule of faith, were not apostolic in origin and were not widely accepted by Christians through the world.
Second, you can be confident that what we read in the New Testament is exactly what God inspired the human authors to write. They are the most carefully transmitted and preserved documents from the ancient world. Even in those rare places where we cannot be 100% sure what the original said, we are always able to determine what it is likely to have said. And there are no places where a central doctrine or belief of the Christian faith is at stake.
So when you open your Bible to read about the good news of who Jesus Christ is and what he was done for us, you can rest your eternal destiny on what you read there. "
If you've thought about how looking into how we arrived at our New Testament cannon of Scripture, this should help.