Not all teaching is defined formally. The church should ‘live’ the word of God, not to merely define it. If “definition” is what you refering as “teaching” such as CCC, then I would say that not all teaching is formally difined.
If A and B are the teachings, and if C is known to consistently follow A and B, then by reason , C is the teaching as well. However any product of reasoning shall be tested time and time again.
It is important to remember that God choose men, not theoretical methodologies neither definitons : He chose to become a man in Jesus. Thus Jesus is God’s ONLY methodology and definition and reason. Not methodologies as in textbooks neither definitions as on paper, but a MAN who believe in God’s will.
Although God’s Will holds the primacy over OUR reasonings, it is believed that His Will ALWAYS follows HIS Most Righteous Reason : Jesus Christ, His own Word, and His Promise. Thus although sometimes His Will is so mysterious for us (outside of our capability to reason), it is firmly believed that “God’s Will is also His Righteous Reason as well”. Now in this way of thinking, we can reason our faith in Him (and His Will) based on the Reason He has revealed to us : Jesus Christ.
Knowing that our reasoning capability is limited, it does not mean that we cannot reason God at all. We can reason God based on His Word and our understanding that God is God of ORDER, and not God of disorder. He has His Reason (His Word), and His Reason is ALWAYS righteous. This righteous reason of God is the absolute truth we seek. Reciprocally the absolute Truth is exactly His Reasoning and also His Will, His own Word and His Promise and the Fulfillment of that Promise : His SELF.
In becoming a man in Jesus Christ, God has given us “a way” to know Him so that we will not be “deceived” by the other false gods. False gods are false reasons. They enter our minds and our souls by making us believe in what is false (a lie).
God of order will not hinder us from knowing Him by becoming “an outrageously unpredictably-out-of-order Being”. Instead He reveal to us His Word who is His Reason who is His Promise who is the Fulfillment of His Promise who is Jesus Christ. In this orderly manner, God teach us His wisdom in many area of our life in our personal relationship with Him. We can have a personal relationship with God because He is a person, not mere “definitions of doctrines” on a piece of paper, nor an impersonal- scientific-full-of-coincidence-universe. God is a personal being, and He Wills His purpose to fulfill His Promise (His Word) in order that He is The Truth.
God’s definition is found in the man Jesus, and consequently in those who believe Him.