5) Should we entertain the possibility that we might be those who fall away? The answer is yes, if we are persisting in attitudes/actions that spring from unbelief.
The apostle Paul entertained the possibility that he might be disqualified if he was not careful how he “ran the race” (1 Corinthians 9:27); and he commanded the arrogant Corinthians to entertain the idea that they might be those who fall away (1 Corinthians 10:12—read this carefully in the context of 9:24-10:13).
8) The biblical teaching of the assurance of salvation must be seen in the context of God’s terrible threats to those who fall into persistent unbelief, and the context of God’s glorious promises to those who trust him.
The way in which we persevere in faith and thereby maintain assurance of salvation is by taking seriously the glorious promises and the terrible threats found in Scripture (cf. Hebrews 10:19-31; also Deuteronomy 28).