my suggestion - pls feel free to reject or amend if its helpful to your meditation.

The problem with the first 2 is that both are same greek word i.e. "may be fulfulled" = "should be fulfilled". Background of verses in John 13 & 19 are hence used to provide my suggested outline. The former is spoken by the Lord in prophetic fulfilment of Judas Iscariot. The other relates to events unfolded during the crucifixtion.

Thanks for food for thought during my lunch time! :)

1. "may be fulfilled" (John 13:18)
- Firmness of God's Word in its Purpose

2. "should be fulfilled" (John 19:36)
- Fortitude of God's Word in its Program

3. "must needs have been fulfilled" (Acts 1:16)
- Fitness of God's Word in its Practice (i.e. application)