Can a believer be sure he would never fall like Israel did?
No, a believer cannot be sure he would never fall like Israel did. Scripture warns that anyone who thinks he stands must take heed lest he fall, because every person is a candidate for falling as Israel did. No one should be puffed up and say such a thing could never happen to him; it can.
Les explains that verse 12 is especially apropos for every one of us: 'Wherefore let him that thinketh he stands, take heed, lest he fall.' He stresses that every one of us are candidates for falling as Israel did. None of us can get puffed up and say, 'Well, that would never happen to me.' Oh, yes, it can. This warning follows the examples of Israel in the wilderness, which were written for our admonition, upon whom the ends of the age are come.
Wherefore let him that thinketh he standeth take heed lest he fall.