When we were living in Siberia, a friend pointed out that it is important when preaching the gospel to an indigenous people to go through the "door" instead of a window. This basically means that it is essential to learn the culture and the language of the people and to find the cultural keys.
Then today I came across these words from Jesus, "I tell you the truth, the man who does not enter the sheep pen by the gate, but climbs in by some other way, is a thief and a robber." It occurred to me that many people who do not respect the culture of the people they are trying to reach actually are thieves in the eyes of the receiving culture. It is often the complaint of Siberian people that they are not interested in Jesus because he is the "Russian god." Anyone who comes preaching Jesus to them without respecting their culture and taking the time to understand them is most definitely seen as a thief. I certainly don't want to be a thief.
Jesus goes on to say, "they will never follow a stranger; in fact, they will run away from him because they do not recognize a stranger's voice". It's pretty plain to see that time is needed for people to learn the voice of the messenger. When the voice is heard, understood and trusted then this is a like the shepherd entering in through the gate.
I hope you will take the time to be a friendly shepherd rather than a thief when sharing the gospel with people.