The Scripture had to be fulfilled.

Acts 1:15-22, In those days Peter stood up among the brothers (the company of persons was in all about 120) and said, “Brothers, the Scripture had to be fulfilled, which the Holy Spirit spoke beforehand by the mouth of David concerning Judas, who became a guide to those who arrested Jesus. For he was numbered among us and was allotted his share in this ministry.” (Now this man acquired a field with the reward of his wickedness, and falling headlong he burst open in the middle and all his bowels gushed out. And it became known to all the inhabitants of Jerusalem, so that the field was called in their own language Akeldama, that is, Field of Blood.) “For it is written in the Book of Psalms, ‘May his camp become desolate, and let there be no one to dwell in it’; and ‘Let another take his office.’ So one of the men who have accompanied us during all the time that the Lord Jesus went in and out among us, beginning from the baptism of John until the day when he was taken up from us—one of these men must become with us a witness to his resurrection.”

Peter was seeing the need to fulfill prophecy right out of the scrpture. One of my teachers noted that this doesn’t exactly fit with the command of Jesus that they were to wait until they received the power of the Holy Spirit. We don’t really know much more about the one who was selected after this time. We do see God sovereignly choosing one who would soon become a chief persecutor of “the way,” a man named Saul destined to become Paul, a powerful apostle. We all have trouble waiting and sometimes we think we have to do things just in case God doesn’t come through. Do we trust Him enough to wait?

Give us Your strength in times of waiting, Lord!

ESV Lectionary