@JesusIs4Me,
Everything the disciple wrote they did not understand; believers today understands more than they did because knowledge has increased. The bible is an historical written account of what the disciples spoke - whether wrong or right.
The disciples understood what was written since they were led by the Holy Spirit to write it.
2 Peter 1:19 We have also a more sure word of prophecy; whereunto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts: 20 Knowing this first, that no prophecy of the scripture is of any private interpretation. 21 For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost.
Peter validated Paul's writings as scripture;
2 Peter 3:15 And account that the longsuffering of our Lord is salvation; even as our beloved brother Paul also according to the wisdom given unto him hath written unto you; 16 As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction. 17 Ye therefore, beloved, seeing ye know these things before, beware lest ye also, being led away with the error of the wicked, fall from your own stedfastness.
More importantly, Jesus validated the sayings of His disciples as scripture; John 15:20 KJV
John 15:20 Remember the word that I said unto you, The servant is not greater than his lord. If they have persecuted me, they will also persecute you; if they have kept my saying, they will keep yours also.
Jesus prophesied that the Father said there will be the need to discern who kept His words from those that did not; John 14:23-24 KJV
John 14:23 Jesus answered and said unto him, If a man love me, he will keep my words: and my Father will love him, and we will come unto him, and make our abode with him. 24 He that loveth me not keepeth not my sayings: and the word which ye hear is not mine, but the Father's which sent me.
Jesus validated scripture as truth;
John 10:34 Jesus answered them, Is it not written in your law, I said, Ye are gods?
35 If he called them gods, unto whom the word of God came, and the scripture cannot be broken; 36 Say ye of him, whom the Father hath sanctified, and sent into the world, Thou blasphemest; because I said, I am the Son of God?
This is what Jesus said to His disciples, testifying that they had ears to hear and understood His sayings.
Matthew 13:10 And the disciples came, and said unto him, Why speakest thou unto them in parables? 11 He answered and said unto them, Because it is given unto you to know the mysteries of the kingdom of heaven, but to them it is not given. 12 For whosoever hath, to him shall be given, and he shall have more abundance: but whosoever hath not, from him shall be taken away even that he hath. 13 Therefore speak I to them in parables: because they seeing see not; and hearing they hear not, neither do they understand. 14 And in them is fulfilled the prophecy of Esaias, which saith, By hearing ye shall hear, and shall not understand; and seeing ye shall see, and shall not perceive: 15 For this people's heart is waxed gross, and their ears are dull of hearing, and their eyes they have closed; lest at any time they should see with their eyes and hear with their ears, and should understand with their heart, and should be converted, and I should heal them.
16 But blessed are your eyes, for they see: and your ears, for they hear. 17 For verily I say unto you, That many prophets and righteous men have desired to see those things which ye see, and have not seen them; and to hear those things which ye hear, and have not heard them.
So your judgment that His disciples did not understand anything they had written is not true. You can make a case for then not always understanding His sayings
before they had written them down for the times they were with Him on earth before His crucifixion, but not at the time they were writing since it was done as led by the Holy Ghost. It would be pointless for them not to understand it and yet we do today? Hardly. More like the other way around.
This was the same with the old covenant believers. Job said, The Lord gives and The Lord takes away. We know this is "not true" when it comes to family or anything else God gives; they are gifts (Jam. 1:17). Job was speaking about what Satan robbed him of. Yes - we know The Lord allowed it, but God did not take anything away from Job. This is how believer speak today.
Job 1:21
And said, Naked came I out of my mother's womb, and naked shall I return thither: the Lord gave, and the Lord hath taken away; blessed be the name of the Lord.
Romans 11:29
For the gifts and calling of God are without repentance.
Many things said by the early church was said and documented as history. What believers must remember above all else is the "Principle" of scripture. God teaches His word is a mystery and only the Spirit can give the understanding of what is written. The Spirit of God's foundation of understanding is the "principles of scripture. GOD'S word does not contradict itself.
I believe you are applying His words NOT rightly dividing the word of truth when you are not considering everything that was written that can easily reprove your "conclusions" from your selected readings. That conclusion cannot be truth if it does not line up with the truths in other scripture in the N.T.
None of the scriptures you presented has to do with the principles of what Jesus came and accomplished.
Those scriptures are to be applied to people that are already believers in Jesus Christ since it is addressing our walking in the light in fellowship with the Father & the Son for how His blood cleanses us presently of all sins. It is when we are not walking in the light and saying we have not sinned, is where a saved believer is lying of his need for forgiveness from Christ Jesus for his sins.
1 John 1:3 That which we have seen and heard declare we unto you, that ye also may have fellowship with us: and truly our fellowship is with the Father, and with his Son Jesus Christ. 4 And these things write we unto you, that your joy may be full. 5 This then is the message which we have heard of him, and declare unto you, that God is light, and in him is no darkness at all. 6 If we say that we have fellowship with him, and walk in darkness, we lie, and do not the truth: 7 But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin. 8 If we say that we have no sin, we deceive ourselves, and the truth is not in us. 9 If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness. 10 If we say that we have not sinned, we make him a liar, and his word is not in us.
All those that seek to abide in Him and His words, should ask Him for help to not hold to any "conclusion" from scripture that does not necessarily line up with the rest of scripture for those that would live as His disciples.
What you preach is about that foundation which can never be removed that was laid by Jesus Christ; but that does not mean a believer cannot sow to the works of the flesh on that foundation, defiling the temple of God with sins for why we need His daily in helping us to walk in the light and in fellowship with the Father & the Son in laying aside every weight AND SIN in running that race in living as His disciple in that reconciled relationship with God thru Jesus Christ.
