One of my favorite lines in any movie comes from Walk Hard: The Dewey Cox Story, which is a spoof comedy. I'm not suggesting you watch it. In fact, I'm suggesting you not watch it. Not only are there graphic scenes that earn it's R rating, but it's a pretty crummy movie in general. I'll give you the one worthwhile line in the whole film. My wife and I quote it pretty often and it never fails to get a giggle. Dewey is trying to nurture his budding music career, and it's taking a toll on his family. His wife Edith is becoming more frustrated about the musician's lifestyle.
“Edith, I’m startin’ to think that maybe you don’t believe in me at all,” Dewey says standing in the doorway of the kitchen. His wife responds with her reassuring southern drawl.
"I do believe in you. I just know you're gonna' fail."
Edith’s ignorant line is funny because it illustrates something the audience knows is self-contradictory. We know what it means to believe in someone. If Edith believed in her husband, it would mean she knows he's going to succeed. She can't believe in him and know he’s going to fail.
You might be wondering what a spoof film from 2007 and the Gospel of John have in common. The answer is, they both expect their audience to know what it means to believe in someone. Even though the idea is reasonably self-evident, it's an essential stop along the way.
The Gospel of John often says that a person must believe in. This phrase is used 36 times in the Gospel and is the primary way Jesus explains what a person has to do to receive eternal life. Any time this wording appears there is an object one is supposed to believe in. Many understand what it means to believe but have tried to add extra meanings to believe in. They claim it means something other than simply believing. Artur Weiser compares the Greek for believes with believes in. His conclusion is that the linguistic variation contains no material distinction. In other words, believes is the same thing as believes in. In another place, he notes that the phrases are used interchangeably. You can see this when you examine what’s in the Gospel of John.
Though believe in is the dominant way Jesus and John describe the requirement for gaining eternal life, it is not the only way it's described. There are various wordings that Jesus uses to describe the requirement for salvation. All of these variations contain the word believe but are followed by different prepositions, and sometimes no preposition at all. The preposition describes the relationship between belief and the object which the belief is directed at. John chapter eight shows that believed Him and believed in Him are the same.
As He spoke these words, many believed in Him. Then Jesus said to those Jews who believed Him... (John 8:30-31)
Obviously, John is using these terms believed in Him and believed Him as synonyms. One is an abbreviation for the other. To believe in Jesus is to believe His words or claims. To believe in Jesus is to believe that He is telling the truth.
It can be further shown that Jesus uses the wording believe that in the same way. In this case, the focus is on the claim He makes.
Therefore they could not believe… Nevertheless even among the rulers, many believed in Him… (John 12:39, 42)
Here, the simple term believe is used as a synonym for believed in Him. This is not the only instance we see synonymous phrases in the Gospel.
The first chapter contains a phrase that appears later in the purpose statement of the Gospel.
But as many as received Him, to them He gave the right to become children of God, to those who believe in His name… believe that Jesus is the Christ, the Son of God, and that believing you may have life in His name. (John 1:12, 20:31)
These two verses appear at the beginning and end of the book, but they reiterate the same idea. The phrase believed in his name only appears once more in the Gospel of John, (John 2:23) but it is clearly a phrase that is synonymous with other phrases about salvation belief. His name means God is salvation. Thus, to believe in His name is to believe in Jesus specifically as God’s salvation.
Another important note from John 20:20-31 (above) comes when we realize that to believe in His name is a synonym for Believing that He is the Christ. In the Gospel of John, Christ was the one who gives free irrevocable eternal life to those who believe in Him. So believing that He's the Christ is the equivalent to believing in Him for that eternal life.
A list of statements about salvation in the Gospel of John shows that the terms, believe, believe in Him, believe in His name, and believe that He is the Christ, The Son of God, are all able to be used interchangeably. Each of these phrases simply look toward Jesus with belief in slightly different ways. There are variations on one idea. One must believe in something, but what is that something.