Mormons tend to shy away from the charged word “predestination” primarily because we’re uncomfortable with its deterministic connotation. We favor the word “foreordination” which feels more friendly to the possibility of rejecting the call or election. While foreordination is doctrinally accurate (Alma 13, Jeremiah 1:4-5) predestination is the actual biblical word (Romans 8:29-30, Ephesians 1:5,11.) But predestination properly understood does not negate Free Will at all.
To have a destination predetermined does not guarantee arrival. If I plan a vacation to Baja but stop and visit friends on the way and waste all my vacation days, it doesn’t mean the destination wasn’t available. My hotel and dining reservations would likely be filled with travelers who may have made a last-minute decision to head south of the border from some delectable oceanic cuisine. They have every right to enjoy the fish tacos I forfeited.
This is in large part what Christ taught in the parable of the marriage feast:
The kingdom of heaven is like unto a certain king, which amade a bmarriage for his son, And sent forth his servants to call them that were bidden to the wedding: and athey would not come. Again, he sent forth other servants, saying, Tell them which are bidden, Behold, I have prepared my dinner: my oxen and my fatlings are killed, and all things are ready: come unto the marriage. But they made light of it, and went their ways, one to his farm, another to his merchandise: And the remnant took his servants, and entreated them spitefully, and slew them. But when the king heard thereof, he was wroth: and he sent forth his armies, and destroyed those murderers, and burned up their city. Then saith he to his servants, The wedding is ready, but they which were bidden were not worthy. Go ye therefore into the highways, and as many as ye shall find, bid to the marriage. So those servants went out into the highways, and agathered together all as many as they found, both bad and good: and the wedding was furnished with guests. And when the king came in to see the guests, he saw there a man which had not on a wedding agarment: And he saith unto him, Friend, how camest thou in hither not having a wedding garment? And he was speechless. Then said the king to the servants, Bind him hand and foot, and take him away, and cast him into aouter darkness; there shall be weeping and gnashing of teeth. For many are acalled, but few are chosen.b
Mathew 2:2-14, KJV
The Feast was prepared for the predestined, and rejected.
Unlike vaycay in Baja, Salvation is not a zero sum affair. The mansions prepared in The Father’s House are open to all who embrace the Christ.