"And after eight days...Jesus came" (Jn 20:26)
Why do Christians meet on Sundays?
Well, that's an obvious one, John: we meet on the first day of the week because that is the day when Jesus rose from the dead, and so we meet to mark it, right?. Well, yes...and no.
That is, I think that there is slightly more to it than that. After all, Jesus certainly had to rise from the dead on some day of the week but it does not automatically follow that He wished them to subsequently mark this day as a new day of worship never previously held by God's people.
I believe the really significant Sunday in this regard is the following Sunday, a week after the resurrection. For it appears that this was the next time that Jesus appeared, as recorded here in John's Gospel (it is stated to be eight days but as they counted inclusively this would be the following Sunday).
We read of no appearances of the risen Christ in the intervening week. There is no suggestion that He popped up on the Monday or on the Wednesday, but rather it appears to have been a full week before the disciples encountered Christ again.
We may say this represents an argument from silence but I think that it is a safe one in this case. Jesus appears to have used at least His initial resurrection appearances to reenforce an important point: He was instituting a change in the weekly calendar of God's people.
Time does not now allow a full discussion of the Sabbath and its meaning in the scriptures but what we do know is that the Jewish followers of Jesus implemented Sunday worship from the earliest days. Clearly this week-long absence followed by a new visitation the following Sunday left a very significant mark on the disciples.
In fact, for all we know all of the pre-ascension encounters with Jesus may have been on Sundays! If so, did the disciples perhaps first get into the habit of meeting on that day during those exciting weeks just on the off-chance that He would come to them again?
What we can say for sure is that a week afer the empty tomb the followers of the Lord received a powerful affirmation that He remained the risen Lord. And now we meet two millennia later in the full confidence that He is still risen!
That is why we are the Sunday People.