The gospels of Matthew, Mark, Luke and John are eye witness accounts.
The New Testament didn’t begin at Matthew, Mark, Luke and John; the New Testament began with the death, burial and resurrection of Jesus Christ.
And the church of Christ was never in existence until Acts 2.
There is a big difference between the New Testament section of the Bible and the New Testament Jesus ratified for the believer.
No one was born again during the earthly walk of Jesus (in the gospels).
Jesus talked to men living under the law and that was the best he could relate with beyond their understanding.
That’s why He told them when the Spirit of truth comes; He shall give us understanding and guide us into all truth.
John 16: 13 [ESV] – When the Spirit of truth comes, he will guide you into all the truth, for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come.
Nobody was ever a son or daughter of God. God was never a father to anyone except Jesus. There was only one son (only begotten son) and that was Jesus (John 3:16) even the Pharisees were offended when Jesus talked about God as His father. To them such statement is a sacrilege.
The disciple have heard Jesus talked so much about His Father, then one of them was bold enough to ask “show us the Father”. Then He answered, if you have seen me, you have also seen the Father.
John 14: 8 [KJV] – Philip saith unto him, Lord, shew us the Father, and it sufficeth us.
John 14: 9 [NIV] – Jesus answered: “Don’t you know me, Philip, even after I have been among you such a long time? Anyone who has seen me has seen the Father. How can you say, ‘Show us the Father’?
All Jesus was doing here is to simplify God to mankind and give a better picture of a father – like God.
Notice here, that Jesus was not yet glorified when he gave them the Lord’s Prayer, and the folks he gave the Lord Prayer to were unbelievers and the church was not yet born.
After His glorification, such prayer is no longer effective.
For example, “And forgive us our debts, as we forgive our debtors.” This means, our forgiveness is dependent on how we forgive others. This does not hold water.
Our forgiveness is based on our faith in the finished works of Christ.
And He is no longer the only begotten son of the father; He is now the firstborn among many brethren.
Romans 8: 29 [KJV] – For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren.
We have become sons of God alongside with Jesus upon salvation; He died and was raised from the dead to give us access to the Father. This was impossible before he died.
The Holy Spirit in each believer teaches him all things (including how to pray, how to forgive, how to live soberly/circumspectly/humbly, walk in love etc. which God used Paul to communicate to us in his epistles and also through other people).
We (believers) have a prayer language now!
We are spirit beings now led by the Spirit, not by some codes or set of rules.
Grace to your heart!