What would historical Jesus studies look like if we started with the things Jesus did first, rather than the words of Jesus? Frequently Historical Jesus studies begin with the words rather than the activities of Jesus. Sayings judged as authentic are then used to decide which things Jesus might have actually done.
In his monograph on the relationship of Jesus and Judaism, E. P. Sanders suggested that this method is backwards. Rather than beginning with the sayings of Jesus, Sanders created a list of activities which we can be certain Jesus did. He then used this list to evaluate the words of Jesus. For Sanders, Jesus’ activity in the Temple becomes the starting point for his study, but any certain activity might be chosen. We know without a doubt Jesus was crucified by the Romans. What might he have taught in order to attract the attention of the Romans? I doubt the Romans went around crucifying people for loving their neighbors. But if someone was implying they were some sort of an “heir of David” and hinting they might be about to restore the kingdom to Israel, perhaps the Romans would respond by arresting and executing the person for challenging the peace of Rome.
This reputation was so well-known that Jesus is described as a “glutton and drunkard” and a friend of “tax–collectors and sinners” (Matt 11:19 / Luke 7:34). This description of Jesus is undoubtedly authentic since it is unlikely such a description would be created by a later Christian community. If you are creating legends to prove Jesus is God, you do not create stories about him eating drinking with prostitutes. Likewise, if you were creating stories to encourage holy living, perhaps you might describe Jesus as a “friend of sinners who have already repented.”
If we know with certainty Jesus ate with sinners, then sayings about welcoming sinners are consistent with those actions. The parable of the Great Banquet in Luke 14 replaces the invited guests with the poor and crippled, as does the Wedding Banquet parable in Matt 22. The often challenged sayings in Mark 2:13-22 may very well be authentic because it is related to Jesus’ practice of feasting rather than fasting.
What other challenged sayings of Jesus that would be less problematic if we started with what Jesus did?