The chief priests and Pharisees were intelligent. Those terms were that the kingdom would be for all men without distinction of race. Very early in His ministry Christ told His hearers of the spirit which must belong to those who join the kingdom. The Sermon on the Mount is such an instruction. However, it defines not the individual's personal relation to God, but the qualifications for being a good member of the kingdom.
All men are under a strict obligation to accept that kingdom.
Sometimes He spoke about His Church as a flock of sheep. It is perfectly clear, then, that Christ had in mind a visible organization which would be as definite as a kingdom or as a flock of sheep. He went about organizing that kingdom from the very beginning. Almost the first thing He did was to gather about Him a group of devoted men whose education in holiness and in their appointed tasks was His most pressing concern. All of the Gospels make a great thing out of the call of the Apostles.