A Resource Ministry Designed to Help People Come Alive to the Wonder, Beauty, and Transforming Power of God's Grace by Magnifying the Cross of Jesus. 
Content Philosophy
Hi, my name is McKay Caston (a brief bio). Thank you so much for visiting!

After 25 years serving as a pastor in small and large, rural and suburban churches in roles ranging from college and career pastor, to senior pastor, and church planter (Creekstone Church), I launched Mustard Seed Publications as a resource ministry designed to provide individuals and churches with distinctively cross-centered discipleship materials that help people come alive to the wonder, beauty, and transforming power of God's grace in Jesus.

Jesus used the metaphor of a mustard seed to describe how the kingdom of God grows from a tiny seed into a flourishing, fruit-producing tree. In each seed, there is gospel power and kingdom potential. Small in size but extensive in scope.

My deep desire is for MSP resources to work like that in your life — seeds of grace that take root and grow, producing the fruit of the Spirit as you abide in Jesus by faith as your perfect righteousness.

As a help to individuals and churches who are in need of digital discipleship materials during the Covid-19 quarantine, ALL MSP RESOURCES, including unlimited license premium materials, are available at NO COST. Just use the coupon code "CORONA-FREE" at checkout.
Meet Dr. McKay Caston

New Articles Every Week

Mustard Seed Publications posts up to five new articles every week on our blog, The Sapling. From issues related to Christian living, to studies in theology and practical helps for pastors, along with guides, templates, and other resources, we hope that you find MSP posts distinctively cross-centered, biblical, enjoyable, and truly helpful - every day.
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Paperback, Kindle, and Printable PDF Versions

Unlike traditional publishers that offer only hardbound and Kindle versions, MSP provides those traditional options while also offering all resources as instantly downloadable digital files that may be viewed like a traditional ebook/Kindle/epub or printed (unlike Kindle) on you own size and style paper with the same formatting of our paperbacks. Just choose "fit to page" to print, bind, and distribute to your small group, church, or class. Each "a la carte" digital resource comes with either a single use license (one copy), small group license (up to 12 copies), or an unlimited license. Just pick what you need and have instant access to the materials.

Use the 100% Off Discount Code on All Resources

As a help to individuals and churches who are in need of digital discipleship materials during the Covid-19 quarantine, ALL MSP RESOURCES, including premium materials, are available at NO COST. Just use the coupon code "CORONA-FREE" at checkout.

Biblical, Redemptive, Enjoyable, and Helpful

BIBLICAL - Most of our resources are tethered to specific texts in the Bible, making them ideal for personal and small group study and discussion.

REDEMPTIVE - Whatever the theme or topic, all of our resources are infused with the primary storyline in the Bible, which is the redemptive message of God’s mercy, grace, and love in the life, death, and resurrection of Jesus.

ENJOYABLE - We hope that as you read and study, you will find that the style of writing, the creativity of layout, the substance of the material so compelling that you will keep turning page after page-not because you have to but because you want to. With engaging stories and illustrations, these resources are intended to draw you through the material so that you make it all the way to the end.

HELPFUL - MSP materials are intended to be more than informational. They are designed to be transformational, genuinely helpful tools that expand your mind, enflame your heart, and enable your hands and feet to follow Jesus in practical ways as you respond to his mercies with a life of faith, hope, and love.

A Sample of FREE Resources

Presently, we offer over 25 FREE resources, with the library growing every week. Get access to the entire MSP free resource library. No obligation. Just free content that you may read on your phone, tablet, or computer, or download, print, and use devotionally or with your staff or family. Subscribe here.
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A Sample of Premium Resources

Most of our premium resources are book length studies based on specific texts of Scripture that include discussion guides, making them ideal for small group Bible studies. 
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This Week's Featured Freebie

It has been said that the night is darkest just before the dawn. That was true for the life and ministry of Jesus. In Passion Week, you will be taken on a devotional journey through the seven most pivotal days in human history. If it feels dark now, be encouraged by hope with Passion Week. There really is a light at the end of the tunnel--even in the darkest of days.

Download and read on your phone, tablet, or computer, or print and use as a devotion for personal or family use.
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New Releases for 2020

At least four new premium resources are being released in 2020. Sign up to be notified when they are available and we will give you a free gift, The Grade Exchange: An Introduction to the Gospel (with small group discussion guide). 
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Content Philosophy

In John 15, Jesus compares the believer’s relationship with God to a branch that receives life from a vine, a fitting metaphor of how personal change takes place, revealing how the concepts of theology, identity, and transformation are inextricably linked.

What we discover in Jesus’ analogy is that change does not take place through greater willpower, determination, promises, and human resolve. Change is the result of a vital union whereby a believer abides in Jesus by faith as his or her sin-bearer, righteousness provider, and fruit producer.

As we abide in the justifying grace of Jesus we receive the sanctifying grace of the Holy Spirit, who gives us new desires and new abilities to produce good fruit. This good fruit is the result of the Spirit’s work in the life of the believer. As we say, the fruit depends on the root.

Therefore, faith-union with Christ as one’s Justifier and Sanctifier is the key to change and provides the theological foundation and spiritual fuel for all the resources available through Mustard Seed Publications.

This is why our mission is to help Christians experience the wonder, beauty, and transforming power of the gospel. When we come alive to the wonder of God’s mercy and grace, everything changes. How I view God and myself. How I engage with the world. How I treat my wife and kids. How I face loss, defeat, and suffering. How I deal with victory and success. Yes, grace changes everything.

If justification is our initial union with Jesus (which takes place through faith), sanctification is our ongoing union with Jesus (which takes place by the same faith through which a sinner is justified).

Three Core Doctrines


At the heart of all of Scripture is the redemptive message of God’s saving grace to sinners in Jesus. Theologically, we call this justification, which is the hub of the theological wheel to which every passage and doctrine is connected. This grace message is the oak from which every acorn of biblical text falls and must be related in order to be properly understood and applied. Or as Martin Luther said, justification is the doctrine upon which the church stands or falls. This is why we are committed to gospel-centered theology. 


Every human either will find his or her core identity in a self-achieved righteousness (or the lack of it) or in a gift-received righteousness. We will functionally live as spiritual orphans trying to make a life and name for ourselves, or we will live like adopted and beloved sons and daughters, with all the freedom, peace, hope, and joy that flows from such an identity. The implications are manifold and wide-ranging, touching on practically every area of life.  This is why we are committed to gospel-focused identity.


What now? Should I expect to experience spiritual change in my life? If so, how does that take place? What is my role in the process?  As Jesus says in John 15, “No one can produce good fruit apart from me.” Practically speaking, this means that we experience the fruit of the Spirit as we consciously abide in the Vine of Jesus’ imputed gift-righteousness. As the Spirit fills us like sap through a vine into a branch, we receive new motives and a new ability to manifest the new life of love, peace, patience, kindness, etc. This is why we are committed to gospel-empowered transformation.

Cross-Centered Theology

The story of redemption is the story of the Bible and of all history. The epicenter of that story is the cross of Jesus, where he becomes a substitute for sinners, taking the place of judgement so that we can be forgiven and free. 

This cross-centered theology is the framework underlying all content created by Mustard Seed Publications.

Substitution is beautifully depicted by C.S. Lewis in his classic, The Lion, the Witch and the Wardrobe, where Aslan is slain upon a stone table in the place of Edmund, the traitor. When Lucy and Susan discover that stone table cracked and that Aslan is not lying there dead as he had been, they come to realize that the curse upon Narnia has been broken.

It is hard to miss the profound Christological imagery Lewis has woven into the story, whether intentionally or not.

Here is how the scene plays out as the sisters hear a deafeningly loud sound of the stone cracking-a crack that ran from end to end.

“Who’s done it?” cried Susan. “What does it mean? Is it more magic?”

“Yes!” said a great voice from behind their backs. “It is more magic.” They looked around. There, shining in the sunrise, larger than they had seen him before, shaking his mane (for it had apparently grown again) stood Aslan himself. “Oh, Aslan!” cried both the children, staring up at him, almost as much frightened as they were glad….”But what does it all mean?” asked Susan when they were somewhat calmer.

“It means,” said Aslan, “that though the Witch knew the Deep Magic, there is a magic deeper still which she did not know. Her knowledge goes back only to the dawn of time. But if she could have looked a little further back, into the stillness and the darkness before Time dawned, she would have read there a different incantation. She would have known that when a willing victim who had committed no treachery was killed in a traitor’s stead, the Table would crack and Death itself would start working backward.”

Integrating cross-centered theology, identity, and transformation, our aim is to reveal how the curse of sin has been broken, not by a Lion upon a table, but by Jesus upon a cross, our substitute in life and death.

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When you sign up to receive occasional email about updates and free resources from MSP designed to help you grow in grace, you'll receive a free copy of The Grade Exchange: An Introduction to the Gospel (with small group discussion guide). 

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