There you go again with another bizarre statement. Sharing the Gospel (or any Bible truth) by definition includes teaching. One would have to refer to certain Scriptures and then expound on them. Take John 3:16 and a Muslim who has never heard this verse. What are you going to do after quoting it? If you do not teach what it means, it will remain a mystery to the Muslim. Just like Philip taught the Ethiopian the contents of Isaiah 53 Christians are obligated to share and teach all at the same time.
During the 1st Century, the only thing done in the synagogues was the reading of the scriptures.
Jesus himself went into the synagogue, as was his custom, on the Sabbath day and read the scriptures and then he sat down.
Jesus also stated my sheep hear my voice and follows after me, another voice ( a voice of a stranger) will they not follow.
Men with Phd's or Rhode scholarships, who are not called, will never be able to understand the bible. The Jews who were given the oracles of God for centuries could not understand the scriptures. That is why the scriptures say - My people are destroyed for lack of knowledge (Hosea 4:6)
When the gospel was first preached by Jesus, there were no scrolls, no bibles, no pamphlets. In fact the gospel was news and good news.
Paul even said, he did not confer with Jesus's disciples about anything, he claimed to have gotten it from God directly.
I would prefer not to pursue this topic of sharing and teaching any further as it has been stalemated. I am sure most people have not read or understood most of what I have written and are just picking up bits and pieces to start an argument.
Lastly because there were no bibles with the complete word of God in the 1st Century, God had to provide teachers, because the good new was completely new material to everyone even to the teachers of the law, many who did not believe it.
Today the bible is given away free and is in most homes and has been around for centuries. If a person never heard the name Jesus or heard of the bible, I would say that he has not been called by God. And God is the one who saves.
Referring back to what you said that Christians are obligated to teach, then that means that Jehovah Witness's, Mormons, Seventh Day Adventists, Calvinists, Catholics, the Christians in the days of slavery who believed in keeping slaves, based on their bible interpretation of slavery etc, etc, etc, maybe hundreds of different sects of Christianity should teach and teach they are doing.
I guess you got what you asked for.