I believe that the Bible (both the Old and New Testaments) is inspired by God and is supremely authoritative. The Scriptures, through narrative and instructions, etc, show us how we can know God. They also show us how we can live lives that please God, lives that will be blessed and used by him.
Here are a couple of resources that I’ve found useful and informative in regards to trusting the authority and authenticity of the New Testament.
The Development of the Canon of New Testament Scripture
The information on this website, collated and organised by Glen Davis, shows the processes by which the Church selected certain writings and deemed them as authoritative, separating them from a larger body of early Christian literature. I like the information on this website and how it has been arranged.
The Reliability of New Testament Scripture
This is an excellent and entertaining video of Dr. Daniel Wallace, Professor of New Testament Studies at Dallas Theological Seminary. In this video Dan Wallace gives a 35-minute talk about textual variants in Greek manuscripts of the New Testament, and how these variations do not undermine our trust in the reliability and message of Scripture. I recommend downloading the pdf of the accompanying powerpoint presentation.
I found the link to this video on Enough Light, the website of my internet friend and DTS student, Laura Spicer Martin.