well I can`t argue with that . There will be times when we can begin from a certain observable point. Your example with mars hill , paul observed there superstitous, and proceeded from there, but nevertheless, again the key elements of the gospel were set forth as in 17: 26 Gods sovereignty 26And hath made of one blood all nations of men for to dwell on all the face of the earth, and hath determined the times before appointed, and the bounds of their habitation; vs 29 The trinity 29Forasmuch then as we are the offspring of God, we ought not to think that the Godhead is like unto gold, or silver, or stone, graven by art and man's device. The deity of christ and his lordship vs 31 31Because he hath appointed a day, in the which he will judge the world in righteousness by that man whom he hath ordained; whereof he hath given assurance unto all men, in that he hath raised him from the dead. Yes, there will be those in different advancements of the truth and God will send that preacher of the gospel to fill that which is lacking in their faith.