your problem is you understood 预定 as TEACH or FORCE,
that is not true!

If 预定是指预定something such as 救恩,
you must conclude that you are saved
because you choose to be saved
and God's 预定 on this particular matter
based on His foreseen capability so the REAL reason
is your decision.

If 预定included Judah's betrayal to Jesus,
you must conclude God FORCE Judah to do bad thing
so that it equaled to God did that bad thing
according to your logic, thus, it is impossible
预定 Judah's betrayal to Jesus, because God never do bad thing
(here good or bad based on your judgement).

so you prefer to accept that
预定是指预定something good
never
指预定something bad
(here good or bad based on your judgement)
预定 blessings
never
cursings
预定 SiChuan WenChuan to be a beautiful place
never
预定 SiChuan WenChuan to be a center of 8.0 earthquake