Too many among those who believe begin doubting and go on doubting, live doubting and die doubting, and go to heaven in a kind of mist.
Many miss the full tide of blessedness the Gospel was meant to convey. Many keep themselves in a low and starved condition of soul, while their Lord is saying, "Eat and drink abundantly, 0 beloved." "Ask and receive, that your joy may be full."
Let us remember then, for one thing, that assurance is to be desired, because of the present comfort and peace it affords. Doubts and fears have power to spoil much of the happiness of a true believer in Christ. Uncertainty and suspense are bad enough in any condition—in the matter of our health, our property, our families, our affections, our earthly callings—but never so bad as in the affairs of our souls. And so long as a believer cannot get beyond "I hope," and "I trust," he manifestly feels a degree of uncertainty about his spiritual state.
The very words imply as much. He says "I hope," because he dares not say, "I know." Now assurance goes far to set a child of God free from this painful kind of bondage. It enables him to feel that the great business of life is a settled business, the great debt a paid debt, the great disease a healed disease, and the great work a finished work; and all other business, diseases, debts, and works, are then by comparison small. In this way assurance makes him patient in tribulation, calm under bereavements, unmoved in sorrow, not afraid of evil tidings, in every condition content, for it gives him a fixedness of heart.
simple faith in Christ shall save a man, though he may never attain to assurance but I will not engage it shall bring him to heaven with strong and abounding consolations.
I believe it is of great importance to keep in view this distinction between faith and assurance. It explains things which an inquirer in religion sometimes finds it hard to understand.
Faith, let us remember, is the root, and assurance is the flower. Doubtless you can never have the flower without the root; but it is no less certain you may have the root and not the flower.
Faith is that poor trembling woman who came behind Jesus in the press, and touched the hem of His garment. (Mark 5. 25.)
Assurance is Stephen standing calmly in the midst of his murderers, and saying, "I see the heavens opened, and the Son of man standing on the right hand of God." (Acts. 7. 56.)
Faith is the penitent thief, crying, "Lord, remember me." (Luke 23. 42.)
Assurance is Job, sitting in the dust, covered with sores, saying, "I know that my Redeemer liveth" (Job 19. 25); "Though He slay me, yet will I trust Him." (Job 13. 15.)
Faith is Peter's drowning cry, as he began to sink: "Lord save, me!" (Matt. 14. 30.)
Assurance is that same Peter declaring before the Council in after times, "This is the stone which was set at nought of you builders, which is become the head of the corner. Neither is there salvation in any other: for there is none other name under heaven given among men, whereby we must be saved." (Acts 4. ll, 12.)
Faith is the anxious, trembling voice, "Lord, I believe: help Thou my unbelief." (Mark 9. 24.)
Assurance is the confident challenge, "Who shall lay anything to the charge of God's elect? Who is he that condemneth?" (Rom. 8. 33, 34.)
Faith is Saul praying in the house ofjudas at Damascus, sorrowful, blind, and alone. (Acts 9. ll.)
Assurance is Paul, the aged prisoner, looking calmly into the grave, and saying, "I know whom I have believed. There is a crown laid up for me." (2 Tim. 1. 12; 4. 8.)
Faith is life. How great the blessing! Who can describe or realize the gulf between life and death? "A living dog is better than a dead lion." (Eccles. 9. 4.) And yet life may be weak, sickly, unhealthy, painful, trying, anxious, weary, burdensome, joyless, smileless to the very end.
Assurance is more than life. It is health, strength, power, vigour, activity, energy, manliness, beauty. It is not a question of "saved or not saved," that lies before us, but of "privilege or no privilege."—It is not a question of peace or no peace, but of great peace or little peace.
Assurance will help a man to bear poverty and loss. It will teach him to say, "I know that I have in heaven a better and more enduring substance. Silver and gold have I none, but grace and glory are mine, and these can never make themselves wings and flee away. Though the fig tree shall not blossom, yet I will rejoice in the Lord." (Habak. 3. 17, l8.)
Assurance will support a child of God under the heaviest bereavements, and assist him to feel "It is well." An assured soul will say, "Though beloved ones are taken from me, yet Jesus is the same, and is alive for evermore. Christ, being raised from the dead, dieth no more. Though my house be not as flesh and blood could wish, yet I have an everlasting covenant, ordered in all things and sure." (2 Kings 4. 26; Heb. 13. 8; Rom. vi. 9; 2 Sam. 23. 5.)
Assurance will enable a man to praise God, and be thankful, even in prison, like Paul and Silas at Philippi. It can give a believer songs even in the darkest night, and joy when all things seem going against him.  (Job 35. 10; Psalm 42. 8.)
Assurance will enable a man to sleep with the full prospect of death on the morrow, like Peter in Herod's dungeon. It will teach him to say, "I will both lay me down in peace and sleep, for Thou, Lord, only makest me to dwell in safety." (Psalm 4. 8.)
Assurance can make a man rejoice to suffer shame for Christ's sake, as the Apostles did when put in prison at Jerusalem. (Acts v. 41.) It will remind him that he may "rejoice and be exceeding glad" (Matt. v. 12), and that there is in heaven an exceeding weight of glory that shall make amends for all. (2 Cor. iv. 17.)
Assurance will enable a believer to meet a violent and painful death without fear, as Stephen did in the beginning of Christ's Church, and as Cranmer, Ridley, Hooper, Latimer, Rogers, and Taylor did in our own land. It will bring to his heart the texts, "Be not afraid of them which kill the body, and after that have no more that they can do." (Luke 12. 4.) "Lord Jesus receive my spirit." (Acts 7. 59.)
Assurance will support a man in pain and sickness, make all his bed, and smooth down his dying pillow. It will enable him to say, "If my earthly house fail, I have a building of God." (2 Cor. v. l.) "I desire to depart and be with Christ." (Phil. i. 23.) "My flesh and my heart may fail, but God is the strength of my heart, and my portion for ever. (Psalm 73. 26.)
The strong consolation which assurance can give in the hour of death is a point of great importance. We may depend on it, we shall never think assurance so precious as when our turn comes to die. In that awful hour there are few believers who do not find out the value and privilege of an "assured hope," whatever they may have thought about it during their lives. General "hopes" and "trusts" are all very well to live upon while the sun shines and the body is strong; but when we come to die, we shall want to be able to say, "I know" and "I feel" The river of death is a cold stream, and we have to cross it alone. No earthly friend can help us. The last enemy, the king of terrors, is a strong foe. When our souls are departing, there is no cordial like the strong wine of assurance.
J.C Ryle. Holiness: It's nature, difficulties, hindrancdes and roots.