The word Backslider comes from the Hebrew word מְשׁוּבָה which means to turn back. Over the years the word has lost some of its meaning and become weak. It is now something we joke about and use in everyday language. It's not a big deal, Everybody does it. I think if we modernize the definition we may see things more clearly. The best way to describe מְשׁוּבָה in modern terms and in this biblical context is to repent from your repentance. You had once repented from walking with the world, so that you could follow Jesus. You went from death unto life, but then you changed your mind. You decided the narrow road really wasn't worth it and returned to the path you were walking before.
An older term used to describe the same concept is Apostasy. In the early church and in times of persecution, the enemies of the Way would torture and maim the early Christians trying to get them to apostatize, to deny their faith. They would be forced to worship a false god or blaspheme the name of Christ. One of the reasons the early church grew so rapidly is that people rarely saw Christians deny the faith and they were struck by a people who stood by their convictions even unto death. They had never seen such faith and the early churches response to persecution and their refusal to apostatize had such a great effect that it eventually transformed the Roman Empire completely.
But today, it has become commonplace to deny our faith in small ways which has made our testimony obsolete and has had the opposite affect that the early church had. We make simple compromises everyday. We deny him with our words and our actions. We refuse to speak for Him because we fear ridicule. We can not handle the idea of being thought of as "old fashioned" or "non-progressive." We would never stand up to true persecution, because if we told the truth we have come to love this world and we hold a firm grip to our place in it. To lose our standing, would be a sentence worse than death. But hear these words from Peter, a man well acquainted with apostasy:
For if, having escaped the world’s impurity through the knowledge of our Lord and Savior Jesus Christ, they are again entangled in these things and defeated, the last state is worse for them than the first. For it would have been better for them not to have known the way of righteousness than, after knowing it, to turn back from the holy command delivered to them. It has happened to them according to the true proverb: A dog returns to its own vomit,, and, “a sow, after washing itself, wallows in the mud.” 2 Pet 2:20-22
So, what is the remedy to this current dilemma? I think it is simple, spend time with Jesus. He should be your rock, the center of your universe, the driving force behind every action. Pray to Him, listen and obey, seek Him, speak of His goodness and you, like Peter, will right the ship, recover from your error and avoid the Shipwreck of your faith (1 Timothy 1:19).