Why did Jesus curse the fig tree in Mark 11, especially since we are told that it wasn’t the season for figs?

Did the Holy Spirit live in believers before Jesus died?

How can we explain the differences in details given in the Gospels?
Intro (First 4 minutes)
Resurrection – How Many Angels? (4:00-11:20)
Crucifixion: Did Jesus Drink the Wine Offered? (11:20-19:29)
Inscription (19:29-22:08)
Who Carried the Cross? (22:08-27:19)
Criminal Behavior (27:19-35:48)
Timeline of Crucifixion (35:48-end of video)

How were people in the Old Testament saved? Could they have had assurance of their salvation?