David Lamb said:
You haven't just heard it - you have probably read it, too. Luke 3.23:
And Jesus himself began to be about thirty years of age, being (as was supposed) the son of Joseph, which was the son of Heli,
The context shows this as the start of His public ministry, which is usually assumed to have lasted about three years. Whether or not that is a correct assumption, He wouldn't
still have been 30 when He was crucified.
(1) Jesus "began to be
about 30 years of age". About 30 describes any age from 27-33.
(2) The Synoptic Gospels (Matthew, Mark, Luke) only focus on
the last 6 months of Jesus' ministry, from John the Baptist's beheading until Jesus' Crucifiction. Please see below for how I reconcile this "6 month ministry" in the Synoptics with the "3-year ministry" of John (and Church Tradition). In short,
John the Baptist's beheading = Luke's start of Jesus' ministry "at about 30". John the Baptist was beheaded in Sept. 36 AD, when Jesus was about (36 - 9 = ) 27 years old, which is "around 30".
Here is my chronology:
John the Baptist's ministry began in 29 AD (Luke 3:1). Jesus was 20 years old at this time (b. 9 AD). (I recall that this is the exact age when Jewish men begin Torah studies.)
Jesus' ministry lasted 3 years, according to Church tradition. Thus, Jesus' ministry must have lasted from 34-37 AD.
I offer that Jesus studied under John, as his disciple, for the previous 5 years (29-34 AD). Jesus' Baptism would have been in 29 AD, and would have begun an intensive 5 year discipleship under John. Jesus "graduated" in 34 AD, and branched out on his own. Both Jesus and John ministered simulataneously for about 2 years (34-36 AD), until John was imprisoned and beheaded.
Jesus was then "on his own" for 6 months (Sept. 36 - Mar. 37 AD).
NOTE: This
perfectly explains the "difference" between the Synoptic Gospels (which only describe a 6 month ministry) and John's Gospel (which clearly mentions 3 full years). The reconciliation is that Jesus' sole ministry all by himself was only 6 months (this is the focus of the Synoptics), but his total ministry was 3 years (as John relates) including a 2.5 year "co-ministry" with John.