1 John 2:14 I write to you, fathers, because you know him who is from the beginning. I write to you, young men, because you are strong, and the word of God abides in you, and you have overcome the evil one. (ESV)
“Fathers” is the vocative masculine plural form of the noun patēr (πατήρ), which is used as a designation for the men in the Christian community who were forty years of age or older.
“Because” is the conjunction hoti (ὅτι), which is employed with the indicative mood of the verb ginōskō in order to form a direct object clause which means that this clause is the direct object of the verb graphō.
This would indicate that John is affirming with the older men in the Christian community in the Roman province of Asia that they were presently existing in the state of knowing Him (Jesus Christ) experientially who is from eternity past.
“You know him who is from the beginning” is composed of the following: (1) second person plural perfect active indicative form of the verb ginōskō (γινώσκω), “you know” (2) accusative masculine singular form of the definite article ho (ὁ), “him who is” (3) preposition apo (ἀπό), “from” (4) genitive feminine singular form of the noun archē (ἀρχή), “beginning.”
The verb ginōskō is in the perfect tense and means, “to know experientially” in the sense of personally encountering, observing or undergoing something through a process.
It also means “to know experientially in the sense of having knowledge or practical wisdom gained from what one has observed, encountered or undergone” and implies being affected by what one meets.
The second person plural form of the verb ginōskō refers to the older men in the Christian community in the Roman province of Asia who were forty years of age or older.
The perfect tense of the verb ginōskō is an intensive perfect, which is used to emphasize the results or present state produced by a past action.
The present state are these older men in the Christian community in the Roman province of Asia who were forty years of age or older knowing Jesus Christ experientially.
The past action is these older men obeying John’s apostolic teaching which communicated Jesus Christ’s Spirit inspired commands and prohibitions.
The accusative masculine singular form of the definite article ho functions as a substantive and means “Him” or “the One” referring to the Lord Jesus Christ and not the Father or the Spirit.
This is indicated by the immediate context since Jesus Christ is the word’s nearest antecedent because His name is mentioned in 1 John 2:12 as being the basis for the Christian community being forgiven their sins when they confess these sins.
Also, the prepositional phrase apʼ archēs (ἀπʼ ἀρχῆς), “from the beginning,” which modifies this article appears in 1 John 1:1 to describe “the Word which is truly life,” which refers to Jesus Christ.
The noun archē means “the beginning, eternity past” implying “something before time, i.e., not a beginning within time, but an absolute beginning, which can be affirmed only of God, of whom no temporal categories can be predicated.”
The word is answering the question as to how long Jesus Christ has existed and thus speaks of His preexistence in that He has existed from eternity past.
The noun archē is in the genitive case and is the object of the preposition apo, which functions as a marker of time which indicates that the prepositional phrase ἀπʼ ἀρχῆς answers the question as to how long the Lord Jesus Christ has existed, namely, from eternity past.
This prepositional phrase does not emphasize kind of time but rather the extent of time.
The Lord Jesus Christ, eternal life incarnate, has always existed from eternity past.
1 John 2:14 I am presently writing to each one of you children that each of you know the Father experientially. I am presently writing to each one of you fathers that each of you know experientially the One from eternity past. I am presently writing to each one of you young men that each of you are strong. Specifically, the Word originating from God is resident in each one of you. Consequently, each of you are victorious over the evil one. (My translation)
The second affirmation in 1 John 2:14 is addressed to the older men in the Christian community and asserts they knew experientially the One from eternity past.
This echoes the first assertion in 1 John 2:13.
They are identical.
In both assertions, John affirms and thus commends the older men in the Christian community as presently existing in the state of knowing Jesus Christ experientially.
This means that they were personally encountering Him through the process of experiential sanctification (i.e. fellowship) as He is revealed in the pages of Scripture and in prayer by God the Holy Spirit.
It also involves being affected by this encounter with the Lord resulting in the gaining of practical spiritual wisdom and more of the character of Christ.
This present state of these older men knowing Jesus Christ experientially was the direct result of the past action of being obedient to John’s apostolic teaching which communicated Jesus Christ’s Spirit inspired commands and prohibitions.
By asserting that these older men knew Christ experientially, John is affirming that they were walking in the light or in other words living their lives according to the standards of God’s holiness which are reflected in the Word of God.
As we noted in our study of 1 John 2:3 and 13, knowing the Lord Jesus Christ experientially is a reference to fellowship with Him.
In other words, it is a synonym for fellowship.
Therefore, to know Jesus Christ experientially is to experience fellowship with Him.
Fellowship with Him and thus knowing Him experientially is based upon observing conscientiously, or in other words, obeying His commandments, which were imparted by Him to His disciples, of which John was one.
Therefore, knowing the Lord experientially is another way to describe fellowship with Him.
Expressions in the Greek New Testament such as “abide in Him, abide in Me, to know experientially, living or walking in the light, in Christ, in Him” are different ways to describe the concept of fellowship.
Fellowship is the experience of the believer after conversion who is experiencing being in the presence of God and this is accomplished by obeying the Father’s will, which is revealed by the Spirit through the communication of the Word of God.
Fellowship for the believer before death or the rapture is “dynamic” meaning it can be lost due to sin but restored by confessing personal sin to the Father (cf. 1 Jn. 1:9).
It is maintained through obedience to the voice of the Spirit who reveals the Father’s will to the believer through the communication of the Word of God.
Fellowship is experiencing eternal life, which again is accomplished through obedience to the voice of the Spirit whose voice is heard through the communication of the Word of God.
It is made possible through the unique theanthropic Person of history, the Lord Jesus Christ, the God-Man.
Specifically, it is made possible because of the merits of Jesus Christ and His finished work on the Cross, which reconciled the world to God, propitiated the holiness of the Father and redeemed every member out of the slave market of sin.
1 John 2:3 teaches that the condition for experiencing fellowship with God is obedience to God’s Word.
It reveals the importance on the part of the believer to be obedient to the voice of the Spirit of truth, who speaks to the believer regarding the will of the Father through the communication of the Word of truth.
The believer who is obedient to the Spirit of truth will experience fellowship whereas the disobedient believer will not.
 Silva, M. (Ed.). (2014). New International Dictionary of New Testament Theology and Exegesis (Second Edition, Vol. 1, p. 416). Grand Rapids, MI: Zondervan.