“The what?” You might rightly ask.
Hardly anyone — unless you’re a huge nerd like me — has heard of this weirdly sounding council.
"Why is this important?”
I am glad you asked.
Before we get into it we need to understand some background. Leading up to this council in 1215 A.D., the role of the pope had been growing from primarily a spiritual leader, to being political power in western Europe and the Mediterranean. For example between 961-985 there was a conflict between German Emperors and the Pope for who could elect bishops and eventually a conflict of who the actual pope was. Kings and popes battled for many years to see who had the true power over the political nature of their kingdoms. In the end with the help of Hildebrand — or Pope Gregory VII — the battle would be won by the papacy.
Papal Reign, Papal Reign (pun intended)
So, for those of us who don’t breath church history, it is at this time that the pope — in Rome — not only controlled the bishops and spiritual authority of the church, but he had the power to also remove kings, give permission for certain nations to invade other, and to even create an international army to conquer lands in the east.
While all of this power was recognized, it was not formalized until the fourth lateran council convened in 1215. At this point the papacy had risen to its most influential point in the history of the church. It was under the leadership of Pope Innocent III that we see the greatest council until the council of Trent (1563) take place. At this council there were more than 400 bishops and 800 abbots and priors present. This is why it is called the 12th ecumenical council in church history.
At this council Innocent III wanted to solidify the pope’s authority to rule over both the church and state. This would formalize extensive power to the pope for centuries to come. As the successor of previous popes, Innocent III was considered — widely — as the vicar of Peter. But now, with a hope to gain universal power, Innocent III started to refer to himself as “the vicar of him of whom it had been affirmed that he was king of kings and lord of lords.” Not only did he claim this to be the case, but the Fourth Lateran Council affirmed it and canonized it. From now on the pope wouldn’t just be the leader of the church, the pope was Jesus’s representative here on earth.
I've got 70 cannons... and most of them are problems
Seventy cannons — along with some guidelines for the crusade — were passed at this council. Again this is why it is regarded as one of the most important councils of church history. Of the seventy cannons passed, a few are worth noting, as their theological importance will shape how the catholic church would operate in the future, and how the reformation would eventually play out.
One notable cannon formalized the belief — that catholics still hold to today — of transubstantiation. This is the belief that, as the catholic catechism states, “(1377) the Eucharist presence of Christ begins at the moment of the consecration and endures as long as the Eucharist species subsist. Christ is present whole and entire in each of the species and whole and entire in each both their parts.” To say it another way, the Lord’s Supper, literally and physically become the body and blood of Jesus.
Another cannon declared that the pope — and the pope alone — could make or break bishops. This cannon only furthered the popes already significant power as both a spiritual and political leader.
These were just a few examples among many others, like the cannon that made it mandatory for Jews to wear a special identifying badge, or the cannon that made disagreement with the pope or the catholic church, an excommunicable offense.
So, why should we care?
The implications of this council were far reaching, both politically and spiritually. As author and professor of history at Denver seminary, Bruce Shelley states in his book, Church History in Plain Language,
“The pope claimed power over … the souls of men and women even in eternity.”
Claims like this lead to some of the most barbaric treatment of humans by christians in the history of the world.
You may have heard the saying, “behind every good man, is a great woman.” The paternalistic nature of the saying aside, it bears some truth as applied to other subjects. When we think of the past sins of the church, many of them couldn’t have been played out without many of the cannons passed at the Fourth Lateran Council. Of the bad things the church did during the middle ages, it was primarily built on the foundation of this council. This is why we aught to know them, that we never forget how power hungry Christians can become. One of the objectives of the Fourth Lateran Council was come swiftly against heresy present in the church, like other great councils in the past had done. But even with its good intentions, it became a force for evil rather than good.
The Epistle of 1 John — rightly — fights false teachers and heresy. Yet in chapter four he reminds the church
“We love because he first loved us. If anyone says, 'I love God,' and hates his brother, he is a liar; for he who does not love his brother whom he has seen cannot love God whom he has not seen.”
John wanted the church never to forget when trying to guard itself against false teachers, it is easy to — yet we must never — neglect the command to love our brother. Christians, we must never forget this truth, no matter how beneficial we may believe our “conquests” to be.
 Kenneth Scott Latourette, “Effort to purify the entire church,” in A History of Christianity, 4th ed., vol. 1 (Prince Press, 2007), pp. 465.  Kenneth Scott Latourette, pp. 471-472.  Kenneth Scott Latourette, pp. 482.  A. Kenneth Curtis, J. Stephen Lang, and Randy Petersen, “The Fourth Lateran Council,” in The 100 Most Important Events in Christian History (Grand Rapids, MI: Fleming H. Revel, 1999), pp. 80-81.  Kenneth Scott Latourette, pp. 483.  “The Celebration of the Christian Mystery,” in Catechism of the Catholic Church (Vatican City: Libreria Editrice Vaticana, 2019), p. 347.  A. Kenneth Curtis, J. Stephen Lang, and Randy Petersen, pp. 80-81.  Bruce Shelley, “Lifted in a Mystic Manner,” in Church History in Plain Language, 5th ed. (S.l.: ZONDERVAN, 2021), pp. 227-228.  The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), 1 Jn 4:19–20.