"But it is clear from the context that Luke doesn't mean they were "sinless""
Luke says they were righteous in the eyes of God and blameless - how then could they have been sinful? This is not at all logical.
"because immediately he recounts the story of Zechariah's unbelief..."
Yes, sure! Zechariah messes up at this point, but you have conveniently forgotten Elizabeth - where does it say that she suddenly lost her righteousness in the eyes of God and became a sinner???
If you spin away the words of scripture here, about Zechariah's righteousness (up to this point), you miss the point that Luke is making. He deliberately sets out to contrast Zechariah and Mary in their response to the annunciations of the baptist's and Christ's births respectively:
a) Both are identified as righteous or full of grace
b) Both are visited by the angel Gabriel
c) Both are troubled by the vision
d) Both are told not to fear
e) Both object
f) Both are promised a sign to confirm the annunciation
And yet one did not believe, and one did believe. Both were righteous: one was righteous by observing all the commandments and ordinances of the Lord blamelessly, yet he did not believe. The other was righteous because she was FULL OF GRACE and she did believe.
Moral : Blessed is she who BELIEVED THROUGH GRACE for faith and salvation do not come through the observance of the works of the law, but through GRACE.
This is St. Paul's and St. Luke's main point presented for us in a nutshell right at the beginning of the Gospel.
If you deny St. Luke's statement that Zechariah was righteous, by claiming he was sinful, then you negate a major point that St. Luke wants to make.
"If John were "sinless" then why would he appeal to Jesus...
......
He recognized that he need to be baptized by Jesus."
The fact that he recognised he needed to be baptised by Jesus does not imply that he was a sinner. If this logic were to be applied, then Jesus' insistence on being baptised by John would imply that Jesus was a sinner. I'm sure you don't believe this!
***Luke says they were righteous in the eyes of God and blameless - how then could they have been sinful? This is not at all logical.***
Sins that are forgiven are not longer a cause for blame.
There is only one person the Bible says never sinned, that person is Jesus...
1 John 3:5
"You know that he appeared to take away sins, and in him there is no sin."
or more literally...
""And sin (the sinful principle) in him is not."
The Bible abounds with references to Jesus' sinlessness, but one is particularly interesting...
2 Cor 5:21
He made the One who did not know sin to be sin for us, so that we might become the righteousness of God in Him.
Interesting to note that Jesus is "the ONE who did not know sin" - as in "the ONLY ONE".
***Moral : Blessed is she who BELIEVED THROUGH GRACE for faith and salvation do not come through the observance of the works of the law, but through GRACE.***
Great point!
BTW: did you know that the word "full of grace" or "enriched with grace" i.e. kecharitomene - is not just used to describe Mary? It is also used to describe Christians in Eph 1:6
"To the praise of the glory of his grace, wherein he hath made us "accepted in" the beloved. In whom we have redemption through his blood, the forgiveness of sins, according to the riches of his grace;"
(kecharitomene). Perfect passive participle of charitom and means endowed with grace (charis).
God's grace and the blood of Christ has made Christians "full of grace".
***If this logic were to be applied, then Jesus' insistence on being baptised by John would imply that Jesus was a sinner. I'm sure you don't believe this!****
Just for this very reason the Gospel writers went OUT OF THEIR WAY to make sure the the reader understood that Jesus was not in need of baptism for the remission of sins but partook in order to "fulfill all righteousness".