"Did Jesus sit on one or two donkeys as he rode into Jerusalem on Palm Sunday? Matthew says Jesus sat on a donkey and a colt, while the other 3 gospels say he sat on a colt. This must be a contradiction."
Jesus only sat on one donkey (the colt) as he rode into Jerusalem (Mark 11:1-10, Luke 19:28-38, John 12:12-15), but brought it’s mother (Matthew 21:1-11). This isn’t a contradiction because Matthew never said Jesus sat on both donkeys at the same time. We have no reason to think the author would make such an odd claim. The most logical explanation is that Jesus sat on the donkeys at different times along the journey. He probably rode the stronger donkey (the mother) on the mile long trek from Bethphage to Jerusalem, then switched to the colt before entering the city. This would also explain why the disciples put their cloaks on both donkeys rather than just the colt.
Another possibility is that when Matthew wrote “Jesus sat on them”, he was referring to the cloaks that the disciples laid on the colt, not the donkeys. In this case, the purpose of the bringing the colt’s mother would be to keep the colt calm since they were still attached to one another. So wether “them’ refers to the cloaks or the donkeys, Matthew doesn’t contradict Mark, Luke, or John.
“Who found the colt: Jesus or his disciples?”
Jesus found the colt (John 12:14) and later told his disciples where to get it (and it’s mother). In John’s shorthand account, he didn’t mention the disciples picking it up (along with many other details). The other gospels don’t directly mention Jesus finding the donkeys, but they make it obvious that he did. Jesus knew exactly where to pick them up and what to say to the owners (Matthew 21:2-3).
Did Jesus sit on the colt, or did the disciples place him on the it as in Luke?
Both. They lifted Jesus like a king, placed him on the colt (Luke 19:35), and he sat down. Matthew, mark, and John don’t mention the disciples lifting Jesus on to the donkey, but it fits within their accounts.
Did the disciples bring Jesus one or two donkeys?
We know from Matthew that they brought two donkeys (Matthew 21:7). The other accounts don’t mention the 2nd donkey, but it’s not a contradiction since they never claim that the disciples only brought one donkey. The two are not mutually exclusive.
Why would Jesus switch to the colt right before entering Jerusalem?
Jesus rode the colt to fulfill prophecy, letting Jerusalem know that he was the messiah.
Did Jesus and his disciples steal the donkeys?
No. When the disciples said “the lord has need of it”, the owners willingly gave it to them to borrow (Mark 11:3). It should be clear that Jesus made prior arrangements (John 12:14), which is also evident based on their response.