"Yea, blessed are the poor in spirit who come unto me, for theirs is the kingdom of heaven."
The blessing referred to for those who are "poor in spirit" comes as a result of "coming unto" Christ. Any who come to Christ will receive "the kingdom of heaven." However, to obtain it, you must "come unto [Christ]."
Christ is approachable. But the approach is determined by the Gospel. The earlier "doctrine of Christ" taught in Chapter 11 tells you how to "come unto Christ."
Belief on His teachings, then repentance and baptism are all essential prerequisites to coming to Him.
What does it mean to be "poor in spirit?" Does that make you more open to Him? Have you ever had a season in which you felt "poor in spirit?" Were you more open to Him as a result?
Before I converted, though I did not consider myself a candidate to convert, I also felt a hollowness in life. There was something missing. The void inside us was meant to be there. Filling it was always the responsibility of the Gospel. We were all meant to feel "poor in spirit" until we find truth. Then, upon finding truth, we were meant to "come unto Christ" so the void may be filled. Coming to Christ is the return to life and light. It is the journey back to that light from where we originated.
Converting was more of a homecoming than anything else. The Gospel rings true and His sheep hear His voice (John 10: 27) because these are things we long ago accepted and decided to follow (Abr. 3: 26-27). Each of us needs to be converted. Even if you were raised in the church, you still need to convert. The steps Christ is outlining are the ones each of us are expected to follow. Whether you do so as an adult, or did so earlier in life, we are all required to "come unto Christ" and be converted.