The Assurance Of Salvation

“The assurance of salvation is not something which is added to the life of faith from without, but something, rather, which blossoms up out of that life of faith itself. Hence, the assurance differs according to the measure of the faith… But all this does not take away from the fact that the saving faith, such as Scripture describes it and the Reformation restored it, is not in its inner nature certainty, and that this certainty becomes stronger in proportion to the extent that the faith becomes stronger. Such faith is not opposed to knowledge, but it is opposed to all doubt whatsoever. Doubt does not come up out of the new man but out of the old; it does not come up out of the Spirit but out of the flesh. The faith says yea and amen to all the promises of God, embraces those promises, and leans upon them. As it does this, and in proportion to the extent that it does so, the refugee confidence of the faith becomes sure confidence, and it gives the believer the freedom to apply all of those promises of God to himself and to appropriate them; the growing confidence becomes a sure confidence that not to others only but to me also the forgiveness of sins, eternal righteousness and salvation have been given of God, out of pure grace, and solely for the merits of Christ.”
Our Reasonable Faith (Eerdmans, 1956). By Herman Bavinck, Page 510-511