Commenting in a sermon on the discussion of apostasy in 1 John 5, Kingsley Barrett says—-
“You cannot ever become so good a Christian as to be secure, beyond all fear of falling.
‘AH Lord, with trembling I confess,
A gracious soul may fall from grace;
The salt may lose its seasoning power,
And never, never, find it more’ (Charles Wesley).
This means you must watch your step when you talk about Christian certainty. Karl Barth once wrote ‘God lends people certitude, but he denies them security.’ That hits it off precisely. God be thanked for the precious loan of certitude, the joyful assurance in which we rejoice, confident that when Christ took away the sins of the world, he took away mine, and there is therefore no condemnation for those that are in Christ Jesus. But beware. The moment you see any Christian, and especially yourself turning this kind of living assurance into security, you may know that there and then he has lost the truth. There is no security but Christ, none in our learning (even in our theological learning), none in our Church and ministry, none in our virtue or religious experience. We have at once the assurance and the insecurity of faith. Idolatry then is possible….
‘Lest that my fearful case should be,
Each moment knit my soul to thee;
And lead me to the mount above,
Through the low vale of humble love. ‘
There are in fact two answers here. The first is Christ. Christ is security, Christ is assurance. These things are not in us, they are not in any institution or rite, however sacred. Christ alone is our rock and defense, our hope and our confidence. ‘All my hope in God is founded!’ Everything else, tower and temple too, will crumble to dust, but he remains. ‘Heaven and earth shall pass away, but my word shall not pass away.’ ‘The grass withers, the flower fades, but the word of our God shall stand forever.’ The next way to lose any Christian assurance you have is to be continually taking your spiritual temperature, and relying on the religious barometer. Take your eyes off of yourself and look at Christ, our righteousness.