What does the Bible say about the certainty of the Gospel?

The Gospel of Luke begins by asserting the certainty of the accounts he is recording, as he aims to provide a detailed and consistent narrative about Jesus Christ. He explicitly mentions that many others have attempted to declare the things 'most surely believed' among Christians. This assurance comes from the fact that Luke either witnessed these events himself or received them from those who did. The certainty of the Gospel is foundational for faith, as it is established on the reliable testimony of eyewitnesses and the inspiration of the Holy Spirit.