Why were the Jerusalem believers destitute in the apostolic days?
The Jerusalem believers had pooled all their resources since Pentecost, and the common treasury ran out, leaving them destitute. Their poverty resulted from obedience to the Word of God, so God provided for them through Gentile believers' offerings, as Paul stressed that the Jews were worthy of material gifts because of the spiritual things given to the Gentiles.
Les explains that the little churches founded in the apostolic days likely met in homes and often lacked full-time pastors. Paul still gave instructions for gathering offerings, primarily for the poor saints dwelling at Jerusalem. Those believers had pooled all their resources since Pentecost, and the common fund had run out, leaving them destitute. Their destitution came through obedience to the Word of God, so God cared for them through Gentile believers' offerings. Paul stressed that the Jews were worthy of material gifts because of the spiritual things given to the Gentiles, and he deals with giving for almost three chapters, 7, 8, and 9.
Therefore, as ye abound in every thing, in faith, and utterance, and knowledge, and in all diligence, and in your love to us, see that ye abound in this grace also.