Introduction: Two Ways to Respond to an Invitation

I don't know whether there is a more terrifying term in the English language than smart casual. Men and women across the nation unite in fear when that phrase appears on an invite — and the internet has made it even worse, with endless guides on how to stand, what to wear, how to get it just right.

But for most of us, what we wear isn't really the thing that gets us in or out of the party. At worst, we get a few funny looks. Yet I've learned that for some people, especially those with a high social standing, what you wear really can be the thing that gets you in or out of the event. And from a bit of research, I've noticed there are two types of people when it comes to responding to an invitation.

The first group struggles to believe that what is written on the invite is actually true. A few weeks ago, a restaurant in Manchester with an explicit policy of no shorts, no sportswear, and no hats was criticised in the local news for turning away a man wearing shorts — tailored shorts, he insisted, on a sunny day. He seemed surprised to be turned away, when really, if he'd just trusted the invitation as it was written, he would have known exactly what to expect.

The second group relies on their own status to get in, no matter what the invitation says. Think of the Icelandic singer Björk, who in 2001 turned up to the Oscars in a full swan costume, laying faux eggs as she walked the red carpet — a total disregard for the expectations of the event's organisers.

So we have two reactions: one that doubts the invitation is true, and one that barges in on its own terms, ignoring what's actually being offered. I think we have a similar instinct when we come to the question Psalm 15 asks.

The Question: Who May Dwell With the Lord?

Lord, who may dwell in your sacred tent? Who may live on your holy mountain? The one whose way of life is blameless, who does what is righteous... (Psalm 15:1-2)

This psalm asks who can look forward to eternity with God — and who can dwell with the Lord even now, this side of the cross. And I think our two groups respond in familiar ways. Some of us read this and feel completely crushed: we could never be like this blameless, righteous one. We doubt God could ever accept us, mired in our sin. We know we're wearing the wrong outfit, so we expect to be turned away. Others of us give up in a different way — we look at the list and think, of course I could never be like that; does it even matter?

But we're called to a much better response. We'll see two points today:

1. We can be thankful for the blameless one (vv1-2a)
2. We are called to live as the righteous one (vv2-5)

Thankful for the Blameless One

Rewind your minds back hundreds of years before Christ. King David, having built the tent that would house God's presence among his people, asks a fundamental question: who could possibly be with the Lord? Who could possibly hope to come near a holy God?

David could have answered in all kinds of ways. He could have talked about ethnicity — only Israelites get to dwell with the Lord. He could have talked about needing a bigger sacrifice. He could have answered moralistically — those who know the Scriptures best and do the most good works. But he doesn't do any of that. Almost the whole psalm instead describes a person's character.```

The answer begins in verse two: the one whose way of life is blameless. It's crucial that we start there, because God's all-inspiring holiness means the only one who can dwell with him must be completely without sin. However well the Israelites tried to live up to the rest of this psalm — never slandering, being kind to neighbours, being wise with money — it wasn't enough. Sin has entered the world, and no matter how hard we try to live the perfect life, God's holiness is so high that nothing but blamelessness will do.

However well you feel your walk with God is going, however on fire for the Lord you may be, this is not a bar any of us are capable of meeting on our own. If you are trying in any way to justify your standing before God based on your own merits, these verses show the futility of that — but they also point us to the wonderful truth that we always needed a mediator.

The Israelites may have thought David himself, the long-promised king, was the answer. But David disappointed, just like every king after him — until we meet the Lord Jesus Christ, who lived a truly blameless life, who did what was righteous, who spoke truth from the heart. He is the blameless one this psalm describes. Through his death and resurrection, if we are trusting in him, we receive his blamelessness, his righteousness, his holiness as our own.

You Are Completely Wiped Clean

As we put our trust in Jesus, our justification and sanctification are definitive — we are completely wiped clean. If you're here wondering, "Is it enough? Will I meet the bar? Can I have assurance of eternity with him?" — or if you feel like the disappointing child God is always angry with — let these verses wash over you and show you what the Lord Jesus has done.

Precisely because God's bar is so high, because his holiness is complete, we simply cannot meet it on our own. It has to be Jesus.

I'll admit that I often respond to passages like this by going through the motions — I'm firmly the type who has "heard this a million times before" and worries a message like this is too basic. But this psalm is so clear: without Jesus, resting only on our own strength, none of us could look forward to eternity with him, none of us could be part of his family. Let's not take this for granted. If you are trusting in Jesus, you are washed clean, taken for eternity by the Creator of the universe. Do you realise how loved you are?

An Illustration of Adoption

Saroo was five years old when he became lost on a train in Kolkata. His brother never returned for him. He was placed in a Kolkata orphanage, where he was miraculously adopted by an Australian couple, Sue and Larry. He later wrote a book describing how, from the moment he arrived, his parents created an environment where he never had to earn his place. They told him they had a vision of him as their son even before he arrived.

"Mom and dad made me feel safe, secure, loved, and above all wanted. I love you, Mom and Dad, and that will never change."

Friends, if you are trusting in the blameless one, that is your story too. You have been adopted by a Father who will never let you go, before whom you are blameless — no matter what you might think — and who loves you completely.

This is also good news to share with friends following religions where Jesus is known but not trusted as the full and complete redemption — those who live terrified of a coming judgment, wondering "Have I done enough?" This psalm is a mighty rebuke to the idea that we can reach God on our own strength, and an enormous encouragement that we have such good news to offer them.

Live as the Righteous One

David doesn't stop at blamelessness. He goes on to describe what those covered by that blamelessness are to do:

...who speaks the truth from their heart, whose tongue utters no slander, who does no wrong to a neighbour and casts no slur on others, who despises a vile person but honours those who fear the Lord, who keeps an oath even when it hurts and does not change their mind, who lends money to the poor without interest, who does not accept a bribe against the innocent. (Psalm 15:2b-5)

David picks out seemingly ordinary aspects of life — not an exhaustive list, but examples of what flows from a changed heart:

• They are careful with how they speak, telling the truth without slandering others.
• They are trustworthy — when they say they will do something, they do it.
• They are wise with their money and use it well.

Notice this isn't about how much of the Bible we know or how well we understand ancient historical settings. It's about character — about how a person lives in light of the sacrifice of the blameless one. This is really the sweep of the whole Bible: how do we grow as Christians? We grow to become more like the Lord Jesus.

We could try to train ourselves into these behaviours through sheer willpower — grudgingly holding our tongue, reluctantly giving money. But for those of us who are secure in Jesus, we don't look at this list and see a burden. We look at it and think: I'd love to be like this person. These outward things are a reflection of an inward love for Jesus, of the Holy Spirit changing us from within.　　

If I didn't slander others, it would reflect that I'm secure in Jesus and want to pour out his love to others. If I kept my promises even when it hurt, it would show that my heart valued others above myself. If I used money wisely and gave generously, it would show that I trusted God with everything, not just the easy parts of life.

A Life Lived Dependently on the Spirit Is Better

It's easy to pine for our old lives — wasn't it so much easier, so much freer, when I could do as I pleased? But that isn't true. A life lived dependently on the Spirit, seeking to be like the righteous one described here, is so much better than a life lived on our own will.

If your response to Jesus' invitation has grown stale, or if there's sin you keep excusing because "it's not that bad," you are living your own way and are mistaken about the life God has made you for. I want to encourage you to want what's on offer here, and to ask the Lord for help in living his way.

One practical suggestion: I've been encouraged recently by examples of people who memorise psalms and use them as the basis for prayer. Wouldn't it be wonderful to commit this psalm to memory, and to pray it as we ask the Lord to help us become more like the one described here?

A Life That Will Not Be Shaken

Whoever does these things will never be shaken. (Psalm 15:5b)

The person who founds their life on trusting the blameless one and living as the righteous one is building on the sturdiest foundation — the promise of eternity to come and the kindness of God. Such a person won't be pushed from pillar to post by the ups and downs of the Christian life the way we would be if relying on our own strength.

Sometimes these words can feel hollow, especially in difficult times when God feels far away. But one of the wonders of church family is that we get to see the reward of a life built on this foundation — and more importantly, we see God's continuing faithfulness in it.

I was chatting with Gordon and Phoebe this week. Gordon has faced a very significant bout of ill health — for a long period, life was a mixture of chemo, A&E visits, and days where simply going down the stairs felt like an achievement. In his miraculous kindness, the Lord has brought Gordon back to the point where he continues to bless our church family even today.

But as I spoke with them, they were clear: it isn't about them, it's about the Lord's abundant and steadying provision. Phoebe described how, through those difficult times, it was only the truth that the Lord was with them in every detail of their lives that kept them going — only his provision of just the right word for that day, only the Spirit keeping them grounded, knowing the prayers of this church family were part of what sustained them. They wanted it made clear: this isn't about them, but about who the Lord is, and what is on offer for those trusting in him.

As we keep going, rooted in him, that is the foundation for a life that will not be shaken.

Conclusion: Two Groups, One Invitation

Let's finish where we began — with our two groups. For those who read the invitation and can't quite believe it's true: I hope this passage encourages you that nothing but the blood of Jesus could bring you close to a holy God. Because of this, if you are trusting in him, you really can approach his holy mountain and dwell with the Lord. Be encouraged by that — and join him, if you haven't already.

For those of us in the second camp — who've accepted the invitation but have slightly forgotten how to behave at the party — may the life of righteousness David describes spur us on to become more and more like the Lord Jesus.

Both groups, in accepting this invitation, can look forward to a life built on the sturdiest foundation: the Lord Jesus, trusted and followed. It is the way to a life that will not be shaken.