I think the important word here is ‘true’. Many people profess Christ but that does not make them a true believer. Many people go to church but that does not make that person a true believer no more than living in a garage makes you a car.
We can see classic examples of false profession in the parable of the sower. In Mark 4, Jesus gives four examples of how someone responds to the word of God when it is sown. This includes church goers and professing Christians. The examples of these seeds sown are as follows:
- The ones sown by the wayside – The word that was sown in their heart is immediately taken away by Satan
- The ones sown on stony ground – These immediately receive the word with gladness but they have no root in themselves, and so endure only for a time. Afterward, when tribulation or persecution arises for the word’s sake, immediately they stumble
- The ones sown among thorns – These are the ones who hear the word but the cares of this world, the deceitfulness of riches, and the desires for other things entering in choke the word, and it becomes unfruitful.
- The ones sown on good ground – These are those who hear the word, accept it, and bear fruit: some thirtyfold, some sixty, and some a hundred.
Now obviously, only God truly knows the heart of a person but EVERYBODY who ‘backslides’ can be put in the first three categories. We know there will be a lot of professing Christians at judgment because Jesus said that MANY will be surprised when he turns them away (Matthew 7:21-23)
Dr John McArthur answers this question thus:
Certainly true Christians can backslide, if by that you mean they can regress into a period of spiritual dullness or disobedience. Those who do so will bring God’s discipline (Hebrews 12:6-11). That’s because God disciplines those who are true sons (v. 8).
But no, if you are thinking of backsliding as a perpetual state of willful rebellion or ungodly indifference on the part of one who professes faith in Christ. That situation is a sign of false profession (Matthew 7:21-23; 1 John 3:4-10).
- The word backsliding is used two ways in Scripture. It is found only in Old Testament references to the nation of Israel (Jeremiah 3:22; 31:22; 49:4; Hosea 4:16; 11:7; 14:4, KJV). Sometimes it speaks of backsliding as the action of unregenerate people who turn stubbornly away from God (cf. Jeremiah 8:5). In that sense the Word cannot be used to describe true Christians.
- Other times true believers are said to backslide (Jeremiah 14:7). All believers go through times when they do not grow or are set back in their growth by sin–they seem to be sliding backwards like a calf on a muddy slope (cf. Hosea 4:16, KJV). In that sense the word could apply to true believers.
Some people confuse this with ‘once saved, always saved so I can do what I want and still go to heaven‘. Paul put it like this
What shall we say then? Shall we continue in sin that grace may abound? Certainly not! How shall we who died to sin live any longer in it? (Rom 6:1-2)
The fact is, if you think like that, then that could be a good indication that you are not truly born again in the first place. If this is the case, it would be a good idea to examine yourself to see if you are truly in the faith. (2 Cor 13:54)