I really appreciate how J. C. Ryle connects personal assurance to bold mission. Ryle writes this in Startling Questions (NYC: 1853), pages 328-29:
Faith is life. How great the blessing! Who can tell the gulf between life and death? Yet life may be weak, sickly, unhealthy, painful, trying, anxious, worn, burdensome, joyless, smileless, to the last.
Assurance is more than life. It is health, strength, power, vigor, activity, energy, manliness, beauty. … Assurance is, after all, no more than a full-grown faith; a masculine faith that grasps Christ’s promise with both hands.
Notice how this two-handed assurance is connected to two-handed mission. He writes in The Upper Room (London: 1888), pages 78-79:
We want throughout Christendom a return to the old paths of the early Christians. The first followers of the Apostles, no doubt, were, like their teachers, “unlearned and ignorant men.” They had no printed books. They had short creeds, and very simple forms of worship. I doubt much if they could have stood an examination in the Thirty-nine Articles, or the Creed of Athanasius, or even in the Church Catechism.
But what they knew they knew thoroughly, believed intensely, and propagated unhesitatingly, with a burning enthusiasm. They grasped with both hands, and not with finger and thumb, the Personality, the Deity, the offices, the mediation, the atoning work, the free and full grace of our Lord Jesus Christ, and the inseparable necessity of repentance, faith, and a Christlike life of holiness, self-denial, and charity. On these truths they lived, and for them they were ready to die.
Armed with these truths, without gold to bribe or the sword to compel assent, they turned the world upside down, confounded the Greek and Roman philosophers, and altered in two or three centuries the whole face of Society.
Can we mend these “old paths”? Can we improve them after eighteen centuries? Does human nature require any different medicine? I believe the bones of the oldest human skeleton that ever was unearthed are just like the bones of men in these days, and I believe the moral nature and hearts of men, after the lapse of ages, are just the same. We had better ask for the ‘old paths.’