Excuse me???
See Jude 3: "The Faith once for all delivered to the saints" is a "recognized body of beliefs" about who God is and what he is doing. In case you don't know it, that is talking about "the essential doctrines" that any church must embrace if it wants to be called a legitimate "Christian" church.
These are the unique doctrines that separate the Christian religion from all other religions.
To step outside of those unique doctines and teach something else, you are stepping outside the Christian religion and teaching FALSE doctrine while calling it "Christian".
Those who claim to speak for God and lead people astray by teaching a different God and a different gospel (anything other than the Christian body of beliefs / essentials beliefs of the Christian religion), are false teachers and Jude says in verse 13 that the worst punishment that God metes out will be their fate.
In verse 3, God (through Jude) is commanding his people to "contend" (strenuous effort) for that unique body of beliefs (THE FAITH) that was once for all entrusted to them so as to prevent false teachers from harming his church.
You may scoff and brush such "strenuous effort" off as unimportant "doctrinal disagreements", but that only tells the world that you don't understand the difference between essential and non-essential doctrines.
There ARE no "doctrinal disagreements" in a truly orthodox Christian church over the "essential" doctrines. Those are set. The squabbles are always over non-essential (meaning non-salvational) doctrines such as baptism and how it should be performed, etc.
Good summary.
Tell you what I have no idea of what church you belong but I will say this much. If I locked you and a dozen members in a room for a month to discuss the Gospel I would dare say each of you would come out calling the other Apostates. Someone would get jealous over anothers faith and demand a higher purity of them. In short no one will ever please you or your church as it is too judgemental. All have sinned and fall short that means me, you, your preacher, mine, and all of us. How then can we be saved? Through GOD all things are possible. My salvation does not depend on what you or your church or anyone elses thinks it should be. My salvation depends on what GOD word says it should be. His word on that matter is simple.
My answering for my convictions is too GOD not Reverand preachers or my neighbors callings and beliefs but that of which GOD through which the Holy Spirit convicts or reveals that I should do. I believe GOD still deals with individuals and ask different task or things of different persons for his divine purposes. GOD did not just say here it is see you in 2000 years.