Looking at the Cross

What is saving faith according to John's Gospel?
Answer: Simply looking at Christ crucified.
John says, "We have seen his glory" (John 1:14) - glory seen most clearly at the Cross where we have received grace on grace.
John the Baptist says, "Behold, the Lamb of God, who takes away the sin of the world" (John 1:29).
Jesus says, "Come and see" (John 1:39).
Philip says, "Come and see" (John 1:46).
The Samaritan woman says, "Come and see" (John 4:29).
The Greeks say, "We want to see Jesus" (IJohn 12:21).
Isaiah "saw his glory" - high and lifted up (John 12:41, Isaiah 6).
At the crucifixion itself the final Scripture to be fulfilled is Zechariah 12:10 - "They will look on the one they have pierced."
Perhaps the clearest a best passage on this in the whole Gospel is John 3:14-15:

"Just as Moses lifted up the snake in the wilderness,
so the Son of Man must be lifted up, that everyone who believes may have eternal life in him."

Read the story in Numbers 21 and the parallel becomes very clear:
"everyone who believes may have eternal life" = "anyone who looks at [the snake on a pole] will live"
Belief, in John's Gospel takes on a very specific meaning - it is looking at the Son of Man / Son of God lifted up on the Cross, looking at him hanging there being made sin for us (2 Cor 5:21), being made a curse for us (Gal. 3:13).
I love this Medieval woodcut for illustrating all the different ways we can avoid looking at the Cross:

1. There's the guy immediately behind Moses with what looks like a mitre on. He's looking sad but he's not looking at the snake on a stick. There are people who know that there’s a problem with the world but they’ve got their back to the Cross. They've rejected God’s solution.
2. There's the guy in the background on the right who is caring for the sick. That's great but he’s not looking at the cross and he’s not pointing the dying man to the cross; if anything he’s turning him away from it. Health care and social action and treating the symptoms of the curse are a very good thing – Christians have always been at the forefront of those things – but if you’re doing that instead of looking at the cross and if you’re not at the same time pointing people to Jesus then you’re both going to end up perishing.
3. Then there's the guy in the top right trying to beat off the snakes. We should be fighting sin in our lives but again he’s not looking at the cross. You cannot save yourself by your will power – what will save us is not some new moral crusade – it is only the Son of God dying for us.
4. And there's the guy lying on the ground. I think he’s supposed to be asleep rather than dead – he’s just oblivious to the danger of the snake slithering towards his head.  We are a culture which is overdosing on spiritual sleeping tablets. We turn on our TVs or open a box set and we want to escape reality, escape thinking about serious issues of life and death and God and eternity.
5. Most subtly there's the guy who seems to be looking at the cross but if you check his direction of gaze carefully he's actually looking at Moses. There have always been people who look at a priest or a vicar for safety rather than Jesus – or to Mary, or the saints, or we might be tempted to look to a Big Name preacher or theologian. No – we must look at Jesus on the Cross. You can imagine Moses saying, like the John the Baptist, “I am not the one – don’t look at me – look at Him – He must increase, I must decrease.”  
6. Only two people - one guy on the far left and Moses himself - are looking at the snake on a stick.

Ultimately there are only two options – looking at the cross or not looking at the cross.
The way we are saved is looking at the Cross.
The way we are transformed is looking at Christ (2 Cor. 3:18).
The way we persevere is fixing our eyes on Him (Heb. 12:2).
So the task of our preaching is to placard Christ crucified for all to see (Gal. 3:1).