Manusia yang merancang, Tuhan yang menentukan segala-galanya

A fren ask me : You always say, manusia yang merancang, Tuhan yang menentukan segala-galanya. Since Tuhan yang menentukan segala-galanya, we don need to plan for anything already, because end of the day, is Tuhan whom determine we suceed or fail!
I personnally believe that, the real meaning behind that statement is that, we still need to plan, however, along our planning process, the last thing we need to rememeber to include in is that, what we have planned for may not be materialized! and during this planning process, we need to prepare to accept this facts!
If we don't prepare to accept this facts, and therefore we don plan to face the possible failure, if the failure do occur, it will be a disaster! I am not suggest tht we plan to fail, but however well and perfect is the planning, end of the day, failure might just knock the door, without we realized it. And if we don prepared ourselves, once it comes, it will be too late!
So any planning, must include the stem of prepare that the plan will not work or fail!