In the last few days of June, 29 A.D., Jesus, just under thirty, came to John to be immersed as a mikveh, a cleansing. John, was immersing those repenting of their sins. He performed these immersions—the most extreme of the cleansing rituals—in the Judean wilderness near Jericho. John tried to dissuade Jesus, basically saying that he needed Jesus to officiate over his own repentance, but Jesus insisted.

Again, we are not given the date of Jesus’ baptism, but it was most likely on Shavu’ot (Pentecost). Here, Jesus experienced the same basic indwelling of the Holy Spirit that his followers would later receive. Considering what Pentecost celebrated and the reasonable certainty that Jesus arrived at the Jordan in this general timeframe, this is a fairly safe assumption. If so, it would have come approximately two months before Jesus’s thirtieth birthday.

Luke says Jesus was "about thirty" as he began his ministry. How much variance would this allow? Could he have been as young as perhaps 27 or as old as 33? This older age would have been the case if the popular 4 B.C. date of birth were true. More likely, this was meant to say that Jesus was within a few months, plus or minus, of his thirtieth birthday.