When I was a teenager, I spent a summer holiday working on a building site. It involved a lot of mixing concrete and cement. Yet when I first properly thought about the building term “cornerstone”, as it appears in 1 Peter 2, it was a little alien.

That’s because modern construction methods don’t require one. We can now construct buildings using concrete foundations made with steel reinforcement bars.

Nowadays, if a building is said to have a cornerstone, it’s just a decorative stone somewhere visible with credits engraved into it.

But in a traditional stone building, the cornerstone is very important. The cornerstone was the first stone to be laid. Every other stone had to be placed in reference to that cornerstone. It determined where exactly the building would be located, what direction it would be in and whether the building was perfectly vertical.

In 2012, Hillsong released its song “Cornerstone”. In its lyrics, we come across:

My hope is built on nothing less
Than Jesus’ blood and righteousness
I dare not trust the sweetest frame
But wholly trust in Jesus’ name

Christ alone, Cornerstone

So we have the notion here of Christians putting Jesus as the cornerstone of their religion – no, actually, their whole lives. Jesus isn’t a wise man or idea or concept that we sometimes turn to when something goes wrong. Instead, he’s the central factor for us to build our lives on.

He’s not like those modern, decorative “cornerstones” in new buildings where the stone has been reduced to a bit of stone with credits engraved into it. For the Christian, he’s a real, critical, foundation.

The idea of Jesus as the cornerstone goes back to the writings of the prophet Isaiah. He writes (in Isaiah 28 v16 NIV):

So this is what the Sovereign Lord says:

“See, I lay a stone in Zion, a tested stone,
a precious cornerstone for a sure foundation;
the one who relies on it
will never be stricken with panic.

“I will make justice the measuring line
and righteousness the plumb line;
hail will sweep away your refuge, the lie,
and water will overflow your hiding place.”

The Biblical Theology Study Bible (edited by D.A. Carson) describes these verses as God pointing to his Messiah (Jesus) revealing true justice and righteousness. “In contrast to the injustice and oppression of the world”, it says, “he will show the world hw it was intended to be ruled.” Zion “will be the true city of God, as opposed to the Jerusalem of human construction”.

In Psalm 118 (NIV) we also come across this:

The stone the builders rejected
has become the cornerstone;
the Lord has done this,
and it is marvellous in our eyes.
The Lord has done it this very day;
let us rejoice today and be glad.

The connects with 1 Peter 2, which describes our relationship with the cornerstone, i.e. Jesus. It talks about how we come to “the living Stone”, i.e. Jesus who has been raised from the dead, who has been “rejected by humans but chosen by God”. We also “like living stones” are “being built into a spiritual house to be a holy priesthood”.

So, in what sense are we a “holy priesthood”? Well, Hebrews tells us that we have “we have a great high priest who has ascended into heaven, Jesus the Son of God”. Then there are also ministerial priests, who exist to serve the holy priesthood. That’s the sense that Paul conveys in Romans 15:

…because of the grace God gave me to be a minister of Christ Jesus to the Gentiles. He gave me the priestly duty of proclaiming the gospel of God, so that the Gentiles might become an offering acceptable to God, sanctified by the Holy Spirit.

But the big idea in this part of 1 Peter 2 is that we are all priests – a priesthood of all believers, built on top of a perfect cornerstone. As Common Worship puts it:

God calls his people to follow Christ, and forms us into a royal priesthood, a holy nation, to declare the wonderful deeds of him who has called us out of darkness into his marvellous light.