amadeus,
The scripture defines this for us.
Contained in the scripture is God's truth but as you see by the contradictory beliefs on this forum and the apparently thousands of church groups based on often exactly the same scriptures that it will take more than your word or mine or the consensus of any group of men to properly sort it out so that we all agree on every point. I see the answer in the following verses [and others], but you will probably disagree even though I am using the scripture that provides the definition. You may say that I am not understanding. Who resolves the difference when two people disagree on the meaning of what is written?
"...God...Who also hath made us able ministers of the new testament; not of the letter, but of the spirit: for the letter killeth, but the spirit giveth life." II Cor 3:5-6
"But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you." John 14:26