Providence
Providence is Gods intelligent plan by which he orders all things to their appointed end. God alone plans all things but he orders things by secondary causes. Just as a good architect himself designs a building and then employs a contractor and craftsmen to build his structure; so, God uses secondary causes to fulfill all that He plans. Of these secondary causes, some are necessary causes and some are contingent causes. Another way of saying this is that some things happen by necessity and other things happen by free choice. Humans and angels have free choice. This may sound unusual, but God, by His providence, conceives and orders things to happen by free choice. This can only be possible because of Gods divine power and because He stands above time.
Predestination
Predestination is a sub-set of Gods providence. Created things are planned and ordered by Gods Providence to their end in one of two ways. One way is that which is right and proper for its nature. For instance the proper end of a rock is to be a rock. A rock doesnt need anything beyond its own nature to fulfill its purpose and destiny other than to be itself"a rock. However, some things that God has created have a purpose above their nature. Humans have the purpose of being united with God which exceeds anything in his nature. Therefore, in order for humans to achieve his divinely appointed purpose, they need Gods supernatural (meaning, "Above nature") assistance. This supernatural assistance is called predestination. God must positively take action on behalf of humans in order to assist them in attaining their divinely appointed (providential) end eternal life. This positive action on Gods part is called grace.
Reprobation
Gods activity is necessary to predestine men to a salvation above their natural capacity. In other words, without Gods intervention and grace, no man could achieve his end, which is union with God. This activity of predestination is a direct act of God. However, God permits those who are resistant to His grace to not achieve their purpose (union with Him). The name for this is reprobation. Reprobation is a purely negative act on Gods part (He allows it to happen). While Gods causal activity (a positive act) is necessary so that humans can be predestined to salvation above their natural capacity, reprobation is not parallel to this. A simple way of saying this is that God saves the saved and the condemmed condem themselves. The guilt for eternal separation from God and the desertion of Gods grace rests with the free will of the person who is reprobated.
It is my view that it is a horrible thing to imagine that God both predestines some people to heaven and some people to hell. This concept is called double predestination and those people who hold to such a doctrine often do not realize that it has been formally anathemized in the West at the Council of Orange in 529 and by the Eastern Orthodox Church since the 1600s. The Council of Orange stated:
"We not only do not believe that any are foreordained to evil by the power of God, but even state with utter abhorrence that if there are those who want to believe so evil a thing, they are anathema."
