Conditional perseverance is the least understood and most controversial of all tenants of Armininian theology.  At its core is the free will of man and the ability to lose one's salvation.  Proponents of this view say that salvation is conditional, the condition being that we keep believing.  If one does not persevere in their belief, they will lose their salvation.

Critics immediately point to scripture that states that nothing can separate us from the love of God and that we are sealed with the Holy Spirit at salvation.  Others decry that we can have no assurance of salvation if in fact we can lose it.

There are different beliefs among even those who hold to conditional perseverance.  Some believe that a person may go back and forth between being saved, then not, then saved once again.  Others hold that once a person has forfeited their salvation there is no going back.  These people are so far gone however that they would never turn back.

Those who believe in conditional perseverance look to passages that call for Christians to continue living holy lives and not to give up the faith.  Other key passages regarding salvation appear to be conditional that a person continues in their belief.

Those who believe in the perseverance of the saints state that turning back is merely hypothetical and that a person who is truly saved will continue in their belief on account that they are saved.

Conditional perseverance should not be made into someone committing so many or so great a sin that God cannot forgive them.  It should not even be considered a mere backsliding in a person's faith.  If salvation can truly be lost, it should be understood that it is through a giving up of the faith that once saved a person.  In the end, the belief hinges on free will.  No one can steal our salvation but if we have free will, we can choose to stop believing. 

If we were elected to salvation (or predestined) and had no choice in the matter, we have absolutely no ability to give back our salvation, even if we should desire to do so.  God is the one who caused us to be saved and there is no way to undo what God has done because we have no free will.

For a more in depth look at this issue, see the article Eternal Security.