Why I'm Positive the New Testament is the Inspired Word of God

I wasn't there when the New Testament was written (nor was anyone reading this), so I need to reference some trustworthy people who were.

JESUS

• Appoints His disciples as apostles, giving them authority to preach and cast out demons (Mark 3:14). 
• Promises to send the Spirit who will guide the apostles into all truth (John 16:13), teach them all things, and bring to their remembrance all that He had said (John 14:26). 
• Sends them out to preach and teach the truths of God under the inspiration and power of the Holy Spirit (Matthew 28:16-20). 

PAUL

• Confirms Jesus’ promise by claiming “we [the apostolic writers] impart this [that is, the truth of God in his letters] in words not taught by human wisdom but taught by the Spirit." (1 Corinthians 2:13) 
• Claims that the word he speaks in his letters is on par with the Word of God (1 Corinthians 14:37, Galatians 1:1, Galatians 1:11-12, 1 Thessalonians 2:13, and many others) 
• Vindicates his character and his lucidity through the logic of his letters and by dying in love for Jesus. 

PETER

• Testifies to the truth of Paul’s letters, considering to them be equal in power and authority to the “other Scriptures.” (2 Peter 3:16) 

THE HOLY SPIRIT

• Witnesses to our hearts through the witness of God, which is greater and more powerful than the witness of men (1 John 5:9). 
• Persuades our hearts through the inner testimony of the Holy Spirit (see Calvin on this) 
• Opens our eyes to see the glory of Christ in the Scriptures (2 Corinthians 4:4-6). 
• Seals the truth of the Scriptures in our heart, which makes us completely and utterly dependent on the Holy Spirit for saving faith, assurance, and certainty that the Bible is God’s Word (John, Paul, Calvin, Westminster Catechism).

John Calvin on the Internal Testimony of the Holy Spirit

“The testimony of the Spirit is more excellent than all reason. For as God alone is a fit witness of himself in his word, the Word will not find acceptance in men’s hearts before it is sealed by the inward testimony of the Spirit. The same Spirit therefore who has spoken through the mouths of the prophets must penetrate into our hearts to persuade us that they faithfully proclaimed what had been divinely commanded . . . because until he illumines their minds, they ever waver among many doubts!” (Institutes, I, vii, 4)

Q. 4. How doth it appear that the Scriptures are of the Word of God?

The Scriptures manifest themselves to be the Word of God, by their majesty and purity; by the consent of all the parts, and the scope of the whole, which is to give all glory to God; by their light and power to convince and convert sinners, to comfort and build up believers unto salvation: but the Spirit of God bearing witness by and with the Scriptures in the heart of man, is alone able fully to persuade it that they are the very Word of God.

-Westminster Confession

Why I Trust the Apostles as Friends

The question often arises in my mind, “How can I trust the apostles in that they conveyed the Word of God and events of the gospels accurately?” 

Aside from the arguments Tim Keller makes about the gospel accounts being too early, too counter-productive, too descriptive, and too costly to be legend (which are great arguments, except for maybe the "too descriptive" one, some Greco-Roman legends can get pretty descriptive, but then again, C.S. Lewis agrees with him that the genre of fiction just doesn't jive with the Bible's texts, and he was a literary scholar), the question is also begged as to whether or not the apostles themselves can be trusted on a personal level, as people. 

It’s often easy to forget that the disciples were humans just like you and I, and were influenced by emotions, hope, and the prospect of their own eternal life.

Motivated by His Glory

They saw “His glory, glory as of the only Son from the Father, full of grace and truth" (John 1:14b) They experienced His salvation. They were converted and loved the glory of Christ and His gospel, just like the followers of Christ today.

They loved Him, followed Him, witnessed His resurrection and witnessed His glory. They were driven by a love for him, and the sweet prospect of eternity with Him in heaven, just like we are today.

One Crucial Difference

Unlike us, however, the twelve disciples and Paul were appointed as apostles by Jesus and given the Holy Spirit to be guided into the truth, taught all things, and brought to remembrance all things Jesus had said (John 14:26, John 16:13). They were inspired by His Spirit to impart and teach the Church (including me) the words and truth of God (Mark 3:14, Matthew 28:16-20).

Starting and Ending with the Glory of Christ

It begins with the disciples witnessing the glory of Christ and believing for themselves, and it ends with the disciples imparting to others the truth of God under the inspiration of the Holy Spirit for the glory of Christ.

John, as well as the other disciples, have experienced an unbelievable salvation and glorious eternal life in Christ, and are constrained by love and by the Savior Himself, to teach me to believe as well. Confirming this is John’s purpose of his entire book: my belief.

 

"...but these are written so that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name. (John 20:31, emphasis added)."

They have nothing to gain by lying to me or deceiving the Church. Just like they have nothing to gain by dying in love for their trust in the Savior.

As such, when John says that he’s written these things about Christ so that I may believe, and when I see the things he’s written accord perfectly with the other gospel accounts, as well as perfectly with the rest of the Scriptures… I believe him and his character, I believe the Savior to which he testifies, and I believe he’s testifying under the appointed inspiration of Jesus that I might believe to the glory of Christ.