According to the New Testament, angels attested to the resurrection of Jesus. Would angels lie?
First of all, the New Testament never claims that any angels actually saw Jesus rise from the dead. Beyond this, the New Testament angelic announcement texts following a supposed resurrection of Jesus create some serious problems. Some of the Gospels allege that angels directed that the disciples should meet Jesus in Galilee (Mark 16:7, Matthew 28:7). While John 21:1 says the disciples went back to Galilee, it is not because of angelic direction. However, the author of Luke claims that the risen Jesus told the disciples that they should stay in Jerusalem (Luke 24:49). Indeed, we see from Luke and Acts the claim that they did stay in Jerusalem and did not go to Galilee. Mark, Matthew and John, of course, contradict this assertion. Whose direction should the disciples have taken - that of the angels (as in Mark and Matthew) or that of Jesus (as in Luke)?
As for the question of whether angels would lie? Well, the author of John writes that Satan, an angel, "is a liar, and the father of lies" (John 8:44). While this is not a Jewish concept, the Christian Bible clearly teaches that angels do lie.