i had a (surprisingly) decent debate with 2 pretty religious christians about this actually. they differed in their opinions and had debates with each other about it.
by decent, i mean that it wasnt just pure bible thumping and emotional..they used logic to back up their religious beliefs more than i had expected.
i said (essentially) that it was impossible to have both simultaneously
one said that there is the divine plan and that everyone has free-will to follow it or not
the other said that free will was given when humanity fell from grace and that there is limited free-will (?) in that God doesnt make decisions for them but that if they act with selflessness and "good" intentions (based on that person's religious tenets specifically, but he granted that other religions arent necessarily false or frowned upon unless other people do bad things intentionally) then they can be in step with the divine plan and in grace without really even knowing it.
i basically responded by saying...if the above is true..then wouldn't free will just be an illusion under that logic? if the divine plan is primary..then wouldnt the free will seemingly exercised already have been pre-determined? So how would there be free will in any given moment if the beginning and end/future have already been scripted out completely? the general response was that people have the choice to be in step with the plan and grace but that there have been so many beings to have existed in the past, currently exist and will exist in the future..plus everything else that has happened, is happening and will happen in general...that 99.999% of individuals do not have enough individual influence or significance to alter the divine plan one way or another and for every one person that doesnt choose to be in grace there is one person that does and everything eventually balances out.
i figured that arguing too much wouldnt really lead to anything and just wanted to get their opinions on it. i disagreed that they can both exist at the same time but found their responses to be interesting despite them side-stepping some things to better fit their stances

one admitted to having some doubt and i pushed him on that and asked if he thought he was truly saved yet based on his own religion and i think he had to pause and think about that for a second