Then Jesus began to teach his disciples that the Son of Man must undergo great suffering, and be rejected by the elders, the chief priests, and the scribes, and be killed, and after three days rise again. He said all this quite openly. And Peter took him aside and began to rebuke him. But turning and looking at his disciples, he rebuked Peter and said, “Get behind me, Satan! For you are setting your mind not on divine things but on human things.” (Mark 8:31-33)

I don’t know if Paul had this story in mind when he wrote today’s chapter of the letter to the Romans, but his rivalry with Peter might have colored the way he painted the story of Abraham’s faith.

Abraham

Before the portion of Genesis that we read this morning (Genesis 17:1-7, 15-16), Abram:

• had already followed God to the land he showed him, “along with his wife Sarai, his brother’s son Lot, and all their possessions, and all the persons they had acquired”
• had already gone down to Egypt because of a famine
• had already separated from Lot so they wouldn’t get in each other’s way, then come back to rescue him
• had already been blessed by Melchizedek
• had already made a covenant with God, and “it was reckoned to him as righteousness”
• and had already had a son, Ishmael, with Sarai’s servant girl Hagar, who went into exile with the boy

Today, God gives Abraham a new name, and God says Sarah will give birth to a son.

Here’s how Abraham responds, at least according to Paul:

He did not weaken in faith when he considered his own body, which was already as good as dead (for he was about a hundred years old), or when he considered the barrenness of Sarah’s womb. No distrust made him waver concerning the promise of God, but he grew strong in his faith as he gave glory to God, being fully convinced that God was able to do what he had promised. Therefore his faith “was reckoned to him as righteousness.” (Romans 4:19-22)

Peter

Now before Jesus started talking about suffering and dying, Simon

• had already left his nets and followed him
• had already seen a man with an unclean spirit healed
• had already seen his mother-in-law healed, for goodness’ sake
• had already seen a leper healed
• had already seen a paralyzed man get up and walk
• had already seen a tax collector leave the money follow Jesus
• had already been appointed one of the Twelve and given a new name, Peter
• had already heard Jesus teach in parables, calm a storm, heal a demoniac, raise a girl to life and heal a suffering woman

And Peter had already gone out on a mission with the rest of the apostles and done all of these impossible things himself!

And then …. Jesus fed 5,000 people, walked on water, cured a deaf man, and fed 4,000 more people.

And then Peter said, “You are the Messiah, the Son of the living God”

Today, Jesus talks about yet another impossible thing: “the Son of Man must undergo great suffering, and be rejected by the elders, the chief priests, and the scribes, and be killed, and after three days rise again.”

Peter starts to argue with Jesus, saying that’s not how it’s going to be! We’re on a roll here – look at everything we’ve accomplished – and it’s just going to keep getting better from now on!

Jesus is sharp in his rebuke, calling Peter on the carpet in front of everyone. “Get behind me, you adversary, you tempter! (That’s what “Satan” means.) You’re focused on human things, not divine.”

I can just imagine Peter’s face burning red with shame.

In his book Falling Upward: A Spirituality for the Two Halves of Life, Richard Rohr writes “Jesus praised faith and trust – even more than love. It takes a foundational trust to fall, or to fail, and not to fall apart.”

How Peter must be humbled by Jesus’ rebuke, though he still has to fall, and fail, a couple more times before he finally falls upward into the identity his name points to: Peter the Rock.

The Mustard Seed

But today I want to turn from rocks, and from the mountain-top where the tempter lives, and focus down on a little mustard seed.

Jesus said, according to Matthew, that “if you have faith the size a mustard seed, you will say to this mountain, ‘Move from here to there,’ and it will move; and nothing will be impossible for you” (Matthew 17:20).

Both Abraham and Peter had trust.

Both of them had seen God acting and had followed God in trust.

Abraham also had just enough faith to be “fully convinced that God was able to do what he had promised.”

That little faith, small as a mustard seed, was “reckoned to him as righteousness.”

However, Peter is most like us – that’s probably why he’s first among the Twelve apostles.

Like Peter, we have already seen Jesus and his Spirit acting in our lives:

• In two powerful Faith Alive weekends that have revitalized the congregation
• In vibrant healing ministries that we offer each other every week
• In so many Bible studies, EfM groups, and reading groups every week
• Through our mission partners and mission prayer links
• Through our children and young people
• In our retired clergy, so generous with their wisdom and time
• In the 85 people who came out on Wednesday night to gather with our bishop for a Lenten study

But like Peter we have a hard time hearing Jesus when the talk turns serious, when he sets his face toward Jerusalem and the cross.

The transformative dying that Jesus describes, what we now call the Way of the Cross, demands of us not just trust that Jesus is leading us where we need to go, but faith that our falling and failing actually moves us upward toward the share in the kingdom that he promises.

That kingdom, Jesus says, is within us (Luke 17:21).

That kingdom, he says, “is like a mustard seed, which, when sown upon the ground, is the smallest of all the seeds on earth; yet when it is sown it grows up and becomes the greatest of all shrubs, and puts forth large branches, so that the birds of the air can make nests in its shade” (Mark 4:31-32).

Jesus says elsewhere that unless a grain of wheat is planted and dies, it cannot rise into new growth (John 12:24).

We are so like Peter in our falling and our failing — afraid to let go of our success, afraid to risk even a tiny mustard seed of faith.

Today, may we be like Abraham, fully convinced that God, in Christ, can do what he has promised.

“For those who want to save their life,” Jesus says, “will lose it, and those who lose their life for my sake, and for the sake of the gospel, will save it.”

Our little faith is enough. Our little mustard seed of faith, if we are willing to lay it down for Jesus’ sake, and for the sake of the good news, is enough.

And that little mustard seed of faith will “be reckoned to us as righteousness,” just as Paul said it would be.

He also said, “The promise rests on grace … “

And the grace of our Lord Jesus Christ, and the love of God, and the fellowship of the Holy Spirit be with us all, now and for ever. Amen.