It is dependent upon what you assume to be the gospel. Since there are only a very few that ever find out what the gate that one must have the faith to use to enter God's kingdom is; the few who do find it will not be endorsing the assumption of the religious majority.
Well, let's assume we are talking about the gospel according to Theodore A. Jones.
Let me ask it this way:
Are you saying that it takes an act of another Christian and that the Holy Spirit can't work through a non-believer to bring the gospel (according to Theodore A. Jones) to another non-believer?
Arern't we all taught by God upon hearing the gospel (according to Theodore A. Jones)? What defrence does it make how are ears hear the word when it is allways the Spirit that brings it to our heart?
John 6:45 "It is written in the prophets, 'AND THEY SHALL ALL BE TAUGHT OF GOD.' Everyone who has heard and learned from the Father, comes to Me.