As “the gospel in a nutshell,” John 3:16 certainly does summarize salvation very nicely. Those words that Jesus spoke to Nicodemus explain clearly that God’s grace is behind people’s salvation. God’s undeserved love, his grace, toward sinners moved him to send his Son into the world to live and die for them. Salvation is God’s free gift through faith in Jesus. Rejection of Jesus Christ merits eternal punishment in hell.
While John 3:16 summarizes the gospel message beautifully, it does not address all the doctrines of the Bible. Realizing that, you wonder why WELS maintains that we need to believe all of Scripture. We hold that position because that is what Scripture itself teaches. The title of your question (“Jesus is the only truth you need”) is helpful in understanding that.
Jesus is the one who said, “Your word is truth” (John 17:17). You notice that there are no qualifying words in Jesus’ statement; he did not say that some or most of God’s Word is truth. He said, “Your word is truth.” All of God’s Word is truth. To hold another position is to deny Jesus’ words. But he who is the Truth (John 14:6) has more to say on the subject.
Jesus said, “The Scripture cannot be broken” (John 10:35). Scripture is a unit. People cannot “break” Scripture by pointing to one part as truth, another part as false and still another as “you decide if it’s true for you.”
How important is it to believe all of Scripture? Jesus said it is what defines discipleship. “If you hold to my teaching, you are really my disciples” (John 8:31). And because the Lord wants all to be his disciples, he charged his followers to “Go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanded you” (Matthew 28:19-20). The Christian Church is to share the gospel of Jesus Christ with others and teach the word of God. You notice what kind of teaching is described: “teaching them to obey everything I have commanded you.” “Everything” rules out the idea that we can be selective in identifying some parts of Scripture as true and other parts as untruthful.
If we go beyond Jesus’ recorded words in the gospels, we find God making this statement about his word: “All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the man of God may be thoroughly equipped for every good work” (2 Timothy 3:16-18). All of Scripture was given by inspiration of God. God gave the writers the very words to write (1 Corinthians 2:13). God always speaks the truth (Numbers 23:19).
In addition, Jesus condemned people like the Pharisees who added to and subtracted from his word (Matthew 23). The New Testament epistles are filled with examples of groups and individuals who denied the truth of God’s word. God’s consistent message is that his followers identify error and testify to the truth (Titus 1:10-11).
“All your words are true” (Psalm 119:160). That was the God-pleasing attitude of the psalmist. That attitude is pleasing to God still today.
Answered by James Pope, professor at Martin Luther College, New Ulm, Minn. Pope is a contributing editor to Forward in Christ magazine. He writes the monthly “Light for our path” question and answer column.