We defended it against those who say it opens the door to rampant sin by pointing out that the elect are those who persevere in faith. With all due respect, men like Charles Stanley who think that people can be saved regardless of having either faith or holiness, are simply wrong. (See his book Eternal Security). Those who would sin with reckless abandon and do not feel the preciousness of faith are not saved.
We looked at the argument that eternal security reduced the warning passages to mere shells by pointing out that they were the acceptable means for keeping the elect on track. At the same time they don't represent the totality of what God will do or how He feels about His sheep.
We mentioned that it's not fatalism, since the mark of a regenerate person is that they persevere in the faith until the end.
These objections aren't surprising. Bring up any classic reformation doctrine such as justification, election, or predestination and you're liable to get the same defensiveness or angry response. Many people are quick to disagree because they believe these doctrines rob God of His loving-kindness and glory. But in fact this is no different than what Paul had to contend against when people said salvation by grace through faith was a terrible idea.
"And why not do evil that good may come?"
"What shall we say then? Are we to continue in sin that grace may abound?
"But if, in our endeavor to be justified in Christ, we too were found to be sinners, is Christ then a minister of sin?
To which the Apostle replied, "Certainly not!"
Far from spurring us on to a total disregard for the things of God, these are the doctrines which cause the heart to sing His praise. Far from emboldening the sinful passions they work to stamp it out completely; it's these in particular that humble you enough to cause you to cast away your own good works. They do not drive you from the heart of God, they bring you along to it. They make you to share in it. These are the doctrines of life. Once Saved Always Saved is the gateway to feeling the depth of God's warm and unconditional love.
So I'll bring this series to a close in the fashion of a conquering Roman General riding his chariot afront the parade and before the cheering onlookers. This doctrine isn't just Scriptural, it's also lovely. It's impressive. it's powerful, and resplendent in glory. Our feeble grip upon God is nothing compared to His mighty grip on us. Our tired, stumbling, and weak wills are nothing compared to His relentless determination to do whatever it takes to save His elect. Even if it means sending His only to be brutalized and put to death by hardened rebels.
I close with the words of Jesus as recorded in John 14:
"Do not let your hearts be troubled. Believe in God, believe also in Me. In My Father’s house are many rooms. If it were not so, would I have told you that I go to prepare a place for you? And if I go and prepare a place for you, I will come again and will take you to Myself, that where I am you may be also."