In John 7:37-39, we read that on the last day, the great day of the feast, Jesus stood and cried out saying, "If anyone thirsts, let him come to Me and drink, adding that whoever believes in Me, out of his heart will flow rivers of living water, referring the future gift of the Holy Spirit, which would be given after His glorification. Jesus chose the time frame of the annual water ceremony celebrated at the end of the Feast annually to connect the symbol to the Holy Spirit and not just physical water. On the last day of the Feast, Jesus proclaims that if anyone thirsts, they can come to Him and partake of the living water which is the Holy Spirit. We know right now that God is calling a select few, but in the Millennium God will call all nations of the world to Jerusalem to be taught by God, to receive His Holy Spirit to know Him and His way of life.