The Bible teaches that repentance from sin and faith in Jesus Christ is the only path to salvation and eternal life. According to Acts 4:12, salvation can only come through the name of Jesus Christ, and this is strongly established in John 3:36, where Jesus Himself said, "He who believes in the Son has everlasting life; and he who does not believe in the Son shall not see life; but the wrath of God abides on him." Therefore, if we believe in the Bible, then we must conclude that there is no other way of salvation than repentance and forgiveness through the blood of Jesus.
What reasons are there, then, to believe that the Bible is the Word of God as it claims to be? Individually, our personal relationship with God as we seek and follow Him can serve as strong subjective evidence. However, there are several areas of objective evidence as well. Among the numerous objective proofs are the fulfillment of Bible prophecy, the scientific accuracy of the Bible and the confirmation of the biblical narrative by archaeology.
One of the most powerful and compelling reasons to believe the Bible is that God has accurately predicted the future throughout history. God Himself offered this as definitive proof of His sovereignty, saying through the prophet Isaiah, "I am God and there is none like Me, declaring the end from the beginning and from ancient times things not yet done" (Isaiah 46:10).
Among these are the detailed prophecies in the book of Daniel about the rise and fall of world empires, which were fulfilled in amazing detail over a period of several hundred years—you can read about them in The Four Empires of Daniel's Prophecies. Additionally, Jesus fulfilled dozens of highly specific prophecies when He came as the Messiah in the flesh, and these prophecies were written by numerous authors over a period of over a thousand years leading up to His human life! A list of Jesus' prophetic fulfillments can be found in our article Jesus' Amazing Fulfillment of Prophecy. Throughout the history of ancient Israel, God repeatedly predicted their future and brought it to pass, and you can find more information about God's interaction with them in The Rise and Fall of Ancient Israel.
Another reason to trust in the Bible is the startling scientific accuracy of the text in light of science, despite having been written thousands of years before modern discoveries. The article God and Astronomy explains the Bible's consistency with astronomical realities long before they were discovered, including the "Big Bang," the roundness of the earth and the fact that our planet is not held up by anything in space. While other ancient religions included many myths and incorrect statements about the universe, the Bible is strikingly accurate.
It is also important to note that history and archaeology overwhelmingly support the biblical record. The list of people, places, and events of the Bible that have been verified by archaeology in modern times is nothing short of staggering. For reference, see our articles Does Archaeology Confirm the Existence of Specific People Mentioned in the Bible? A Staggering Archaeological Discovery: The Mighty Assyrian Empire Emerges from the Dust, and many others under the Archaeology tag on UCG.org.
No other religious book even comes close to the Bible on its scientific and historical accuracy, or the immense number of fulfilled prophecies it contains. Given the weight of evidence supporting the Bible as the Word of God, we can trust what it says about how to live our lives, how to enter into a relationship with God and how to receive eternal life. The Bible clearly states that repentance and faith in Jesus Christ is the only way to receive salvation. And that's how we can know that Christianity is indeed the one true religion.