For one person to have a relationship with another, there must be two-way communication. No personal relationship can exist without this communication. We speak often of a "personal relationship with Jesus Christ," and rightly so, but unless there is personal communication, this relationship does not exist. Many have missed this element. They pray to God, but they do not know Him speaking to them. Others read the Bible and assume that God spoke everything He had to say to those who wrote the scriptures. They read the Bible to listen to God, but do not know the personal divine element of God speaking through the scriptures to them. This allows men to "pick and choose" out of the written Word of God what is convenient for their own situation, and ignore other parts as having been written to others.
The scriptures truly were written as men were moved on by the Holy Spirit, but the Lord did not leave us with only a book. He promised that He would not leave us as orphans, but that He would come to us. "But the Helper, the Holy Spirit, whom the Father will send in My name, He will teach you all things, and bring to your remembrance all things that I said to you" (John 14:26). This promise was fulfilled on the Day of Pentecost, and Peter made it very plain that it was not just to those who were there on that day, but "to all who are afar off" as well. As we shall see, this was the beginning of a new personal relationship with God that the saints under the Old Covenant did not have.