γνοσις as related to salvation
What knowledge must one possess to be saved? This is a complex question, and the answer is both simple and complex at the same time. First of all let me state that one is not saved by the acquisition of facts. One is also not saved by faith in facts; facts can be wrong. Salvation comes to us through belief in Christ.
Romans 10:14 may help us understand the roll that knowledge plays. "How then will they call on Him in whom they have not believed? How will they believe in Him whom they have not heard? And how will they hear without a preacher?" The very core of this verse is that you cannot believe unless you have heard about it, you cannot hear about it unless someone tells you.
God's general revelation can only take you so far. It can let you know that he is there, but it cannot tell you anything specific about the person of God. The specificity about God comes from the bible. You may be able to say to one person that the bible is the word of God, and that person will believe you. Another person may say "how do I know that it is the word of God?" And at this point you would have to provide them with more information to bring them to a "beyond a reasonable doubt" conclusion. This is true for anything relating to God and salvation.
What I am trying to say is that depending upon the person who is doing the hearing is the amount of knowledge that will be required. You may be able to say to one person "believe on the Lord Jesus Christ and you shall be saved." And they will, but another person may have to be shown that first there is a God, then that there is a Christ, and so on, before they will believe; if they ever do believe.
One person's hearing begins with another person's telling. Even before Christ began his ministry John the Baptist came to prepare His way. This was spelled out in Luke 1:77 where it states: "To give to His people the knowledge of salvation By the forgiveness of their sins." That was John the Baptists' ministry. Just as he told of the coming messiah we are to tell of the messiah who came.
in your moral excellence, knowledge
ἐν δὲ τῇ ἀρετῇ τὴν γνῶσιν
The knowledge word that we have here is γνο͂σις (gnosis, G1108) and can be defined as: to know. Knowledge. Present and fragmentary knowledge as contrasted with epígnōsis (G1922), clear and exact knowledge…
I know that E=MC2. I have no understanding of what that means; therefore I cannot apply that knowledge. I know that 1 + 1 = 2 and I understand what that means. I can even apply that knowledge. γνοσις is knowledge without necessarily understanding how to use that knowledge.
γνοσις is used 29 times in the new testament and all but six uses are by Paul. Two are by Luke and four are by Peter. The order that we will examine the verses in is as follows: γνοσις as related to God, γνοσις as related to salvation, and finally, γνοσις as related to the Christians life.
γνοσις as related to God
"Oh, the depth of the riches both of the wisdom and knowledge of God!" Romans 11:33
Knowledge begins with God. It would be correct to state that God is knowledge. Or another way of saying it would be that God is omniscience. Omniscience means that: "God knows everything- past, present and future. He knows the actual and the possible; only the impossible (the contradictory) is outside the knowledge of God." Because of this God is able to say: "Remember the former things long past, For I am God, and there is no other; I am God, and there is no one like Me, Declaring the end from the beginning," (Isa. 46:9-10) God knows what has happened, what will happen, and all of the what ifs. (Matthew 11:21-23) Since God is the embodiment of all knowledge if we are to know anything God must reveal it. This does not just apply to spiritual things but also to earthly things. (Dan. 2:20-23) Deuteronomy 29:29 tells us that the secret things belong to God but that things revealed belong to us and our descendants.
God reveals things to us through natural revelation and through specific revelation. God uses natural revelation to not only point out that He is there but also to make life on earth possible. We are able to eat, and build things because God has revealed His laws that govern how those things and others work. What we call mathematics and science is just our understanding of knowledge revealed by God and put to use by us. Knowledge gained by natural revelation works whether we acknowledge God or not. Another term for this is common grace.
Specific revelation is what God has revealed to us through His Word and can only be understood by spiritual means. (1 Cor. 2:14-16) In this passage the word translated natural man is ψυχικὸς (psychikos, G5591) and means soul. And is contrasted with "he who is spiritual" (vs. 15) Spiritual is the word πνευματικὸς (pneumatikos, G4152) and refers to the third part of what makes up a human. As humans we are tri-part creatures. We are body, soul and spirit. Depending upon how you interpret scripture, in the unbeliever either they do not have a human spirit (they get this at salvation) or they have a human spirit that is dead (it becomes alive at salvation). Either way you believe (my mind is not made up on this matter) the unbeliever has no way to discern spiritual things. (vs. 14) Once a person becomes a believer in Christ then that person is able to discern spiritual things. (vs. 15) This discernment begins with learning (knowledge) the bible. We do this through both personal bible study (2 Tim. 2:15) and through bible class (church) (Heb. 1:23-25). As we gain knowledge we will gain understanding that will lead to "full knowledge" which will be discussed latter in full detail.
One final thought if you want to know God the only way to do so is to know Christ, this is because of Col. 2:2-3 as compared with John 14:9.