Is Once Save Always Saved Biblical?

This article is a response to the video blog Allen Parr did on the same question. That video can be found here:

Before I address some of the points made in this video I would like to lay some groundwork. First lets cover some terminology. The OSAS (once saved always saved) view is formally or theologically known as the doctrine of Eternal Security and falls under the doctrinal discipline or category of Soteriology. It is very much rooted in some Reformed Systematic Theology, particularly Calvinism’s views on predestination and its, TULIP, core principles. Many good Christians have quite different views on Eternal Security and while it shouldn’t be a dividing point it often does cause robust disagreement and at times division and can affect how one views the Christian faith and life circumstances. So, while it is not something that should divide the church it is not an unimportant doctrine.