John Murray: The Distinction Between the "Basis of Salvation" and the "Basis of Assurance of Salvation"

"When we speak of the grounds of assurance, we are thinking of the ways in which a believer comes to entertain this assurance, not of the grounds on which his salvation rests. The grounds of salvation are as secure for the person who does not have full assurance as for the person who has."

(John Murray, "The Assurance of Faith," in Collected Writings of John Muray, Volume 2: Systematic Theology, p. 270).