Dear friends, although I have been eager to write to you about our common salvation, I now feel compelled instead to write to encourage you to contend earnestly for the faith that was once for all entrusted to the saints. (Jude 1:3, NET)

Form focuses on what something is. Function on the other hand, focuses on what something does.

Let me explain this in another way, in terms of my vocation: 

An individual would quickly recognize I am a firefighter, because of my uniform, or the equipment I wear (Form). Similarly, an individual would recognize a firefighter by their job, climbing ladders, spraying fire hoses and rescuing people from danger. 

In Christianity, there is an essential form. We are saved. We have this common salvation. It is what denotes, separates or identifies us. Hopefully those around you can plainly see you’re a Christian. 

As an example, in Matthew 25, Christ presents two possible forms for humans, either a sheep or goat.

​​32 All the nations will be gathered before him, and he will separate the people one from another as a shepherd separates the sheep from the goats. 33 He will put the sheep on his right and the goats on his left. (Matthew 25, NIV)

As Christians, we have essential functions as well. The life of faith produces good works in every opportunity the Lord gives. 

The King will reply, ‘Truly I tell you, whatever you did for one of the least of these brothers and sisters of mine, you did for me (Matthew 25:40, NIV)

So why does this matter, and what does it have to do with Jude? At different times it may be more pressing to discuss form, at others times function. You could compare this to the need for systematic theology and then at other times practical or applied theology.

Jude initially says he was eager to discuss what I would call form, that is, at least in this case, common salvation. I love getting together to talk with my Christian brothers and sisters to talk about what unifies us. To talk broadly about the “forms” of Christianity. What our faith looks like in the daily life. It is a good practice even to take these sorts of “long walks along familiar paths” to strengthen our understanding and worship. Even in our Reformed circles we dwell on the form of salvation; according to Scripture alone, by Christ alone, in faith alone, because of grace alone, for glory to God alone. This is good, for this common salvation gives us our firm foundation of faith. 

But then, there is time for function. 

In Jude’s time, the Church was under attack from the inside out. Hearing this, the Spirit compelled him to write not about the faith, but now to write for the faith.

In the verses that follow, Jude is going to present some very uncommon things and use them to encourage the Faithful to be ready to contend (fight) earnestly to take back faith. Not the act of believing (form) but the actual doctrinal beliefs of those who believed (functions). 

You see, its great to join in unity and share common faith, but we can’t deconstruct Christianity in the process. Doctrine really does matter! Without doctrine, we are vulnerable to evil men. This has given an opportunity for the rise of liberal theology and non congruence across mainstream churches for nearly 200 years. It has weakened our functions, and torn down our forms. Some “Christian” organizations are not recognizable by form or function anymore! Then there are those who claim to be, but do not act as if they truly are (e.g., The Episcopal Church). Yet others that claim not to be but still try to perform the functions of church (e.g., Alcoholic Anonymous). 

Doctrine has been entrusted to us by those that came before us. We now carry the torch. Let us not extinguish the flames of faith and instead ignite the next generation! Don’t shy away from doctrine, or settle for shallow theology. Don’t be afraid to stand firm on the truth of Scripture, and to defend it!

Paul warns us similarly in Romans 16:17: “Watch out for those who cause divisions and create obstacles contrary to the doctrine that you have been taught; avoid them.”

I love this video about how doctrine awakens the mind.

and this on the importance of theology.

Peace be with you.