Lewis Sperry Chafer wrote in his 1917 work, Salvation (reprinted by Zondervan 1980), ” From the testimony of Scripture a Christian should know that he is saved . . . Where there is a lack of assurance there is usually an impression that so long as the life is quite imperfect (and how immodest it would be to claim that it is otherwise) it is unreasonable to do any more than hope that through some special exercise of mercy on God’s part it will not be as bad in the end as it might otherwise be. Unwittingly such attitudes of mind disclose the appalling fact that persons who hold such views [quite possibly]1 have never turned from dependence on their own works and merit to a dependence on the all-sufficient work and merit of Christ. If salvation depends in any degree on personal goodness, there could not be even a saved person in the world, and therefore no ground in it for assurance. Salvation is not offered to those who have purposed to be good, or religious . . . It is offered to all meritless, helpless sinners who are willing to believe that God has already been good in that He has provided, in Christ, not only what they need now, but all they need in time and for eternity. This, too, is believed on no other evidence than that God has said it in His Word. In looking away from self and one’s failure to Christ and His saving grace, one will find adequate grounds for a God-honoring certainty as to position and destiny in Christ Jesus” (pp. 57-58).
1Chafer indicated shortly after this that a person could lack assurance and be a believer. See page 58.