In Christian theology, assurance refers to a believer's confidence in God, in God's response to prayer, and in the hope of eternal salvation. In Protestant Christian doctrine, the term "assurance", also known as the Witness of the Spirit, affirms that the inner witness of the Holy Spirit allows the Christian disciple to know that they are justified. Based on the writings of St. Augustine of Hippo, assurance was historically an important doctrine in Lutheranism and Reformed Christianity, and remains a distinguishing doctrine of Methodism, although there are differences among these Christian traditions. Hymns that celebrate the witness of the Holy Spirit, such as Fanny Crosby's "Blessed Assurance", are sung in Christian liturgies to celebrate the belief in assurance.
Methodism Wesleyan Methodism The Historical Statement in The Book of Discipline of the Southern Congregational Methodist Church offers a background on the Witness of the Holy Spirit:
John Wesley believed that all Christians have a faith which implies an assurance of God's forgiving love, and that one would feel that assurance, or the "witness of the Spirit". This understanding is grounded in Paul's affirmation, "...ye have received the Spirit of adoption, whereby we cry Abba, Father. The same Spirit beareth witness with our spirits, that we are the children of God..." (Romans 8:15–16, Wesley's translation). This experience was mirrored for Wesley in his Aldersgate experience wherein he "knew" he was loved by God and that his sins were forgiven.
"I felt my heart strangely warmed. I felt I did trust in Christ, Christ alone for salvation, and an assurance was given me that He had taken my sin, even mine."—Wesley's Journal.
Early in his ministry Wesley had to defend his understanding of assurance. In 1738, Arthur Bedford had published a sermon in which he misquoted Wesley's teachings. Bedford had misunderstood Wesley as saying that a Christian could be assured of persevering in a state of salvation, the Reformed (Calvinistic) view.
In a letter dated September 28, 1738, Wesley wrote, "The assurance of which I alone speak I should not choose to call an assurance of salvation, but rather (with the Scriptures), the assurance of faith. ...[This] is not the essence of faith, but a distinct gift of the Holy Ghost, whereby God shines upon his own work, and shows us that we are justified through faith in Christ. ...The 'full assurance of faith' (Hebrews 10.22) is 'neither more nor less than hope; or a conviction, wrought in us by the Holy Ghost, that we have a measure of the true faith in Christ.'"The discussion of Wesley's understanding of assurance is a revision of information presented on the website "Days of Wesley", copyright 2004, Days of Wesley, Conrad Archer, Entry on Assurance .
The full assurance of faith taught by Wesleyan Methodists is the Holy Spirit's witness to a person who has been regenerated and entirely sanctified. This full assurance of faith "excludes all doubt and fear since the heart has now been perfected in love", consistent with a Wesleyan–Arminian interpretation of 1 John 4:18, which proclaims "There is no fear in love; but perfect love casteth out fear: because fear hath torment. He that feareth is not made perfect in love.": KJV John Wesley emphasized that this is not an assurance about the future, but about the present state of the believer (Methodist theology teaches that apostasy can occur through sin or a loss of faith). Believers can be assured that they are the adopted children of God and will be with him for eternity if they continue in holiness by trusting in Christ and obeying God's commandments in this life.
The Pilgrim Nazarene Church, a Wesleyan Methodist denomination in the conservative holiness tradition, teaches:
The Emmanuel Association of Churches, another Wesleyan Methodist denomination, states:
Methodist hymnody includes a number of Christians hymns dedicated to the doctrine of the Witness of the Spirit, such as Blessed Assurance (by Fanny Crosby), He is Mine (by James Rowe), and Wonderful Peace (by Haldor Lillenas).
Calvinistic Methodism Calvinistic Methodists teach that "one who had been justified by faith could have the inner, personal assurance of their acceptance with God through the witness of the Spirit." In contrast, with respect to traditional Reformed theology, "Calvin believed the inner testimony of the Holy Spirit confirmed the authority of Scripture instead of confirming inwardly one's assurance of salvation; although Calvin believed the Spirit was the agent who joined the believer to Christ."
Quakerism The Central Yearly Meeting of Friends, a Holiness Quaker denomination, teaches in reference to the experiences of the New Birth and Perfection "that the Spirit of God gives to each born again person an inward witness that he is truly a child of God and to each truly sanctified person a witness that he is entirely sanctified." Quakers hold that the "witness of the Spirit is nothing more than the communication and assurance of God through the Spirit to the inward consciousness of the seeking and the believing soul that he has received that which he desired of God, that God has both hear the prayer and performed His work of grace in the heart (Rom 8;16; I Jn. 5:14, 15)."
Baptists Baptists teach that a "person is born again when he/she believes on the gospel of the Lord Jesus Christ (the death, burial, and resurrection) and he/she calls upon the name of the Lord." Those who have been born again, according to Baptist teaching, know that they are "a child of God because the Holy Spirit witnesses to them that they are."
Lutheranism
Lutheranism accepts monergism, which states that salvation is by God's act alone, and rejects the teaching that humans in their fallen state have a free will concerning spiritual matters.1 Cor. 2:14, 12:3, Rom. 8:7, Martin Chemnitz, Examination of the Council of Trent: Vol. I. Trans. Fred Kramer, St. Louis: Concordia Publishing House, 1971, pp. 409–453, "Seventh Topic, Concerning Free Will: From the Decree of the Sixth Session of the Council of Trent". Lutherans believe that although humans have free will concerning civil righteousness, they cannot work spiritual righteousness without the Holy Spirit, since righteousness in the heart cannot be wrought in the absence of the Holy Spirit.Augsburg Confession, Article 18, Of Free Will . Lutherans believe that the elect are predestined to salvation.Acts 13:48, Eph. 1:4–11, Epitome of the Formula of Concord, Article 11, Election , Mueller, J.T., Christian Dogmatics. St. Louis: Concordia Publishing House, 1934. pp. 585–589, section "The Doctrine of Eternal Election: 1. The Definition of the Term", and Engelder, T.E.W., Popular Symbolics. St. Louis: Concordia Publishing House, 1934. pp. 124–128, Part XXXI. "The Election of Grace", paragraph 176. According to Lutheranism, Christians should be assured that they are among the predestined.2 Thess. 2:13, Mueller, J. T., Christian Dogmatics. St. Louis: Concordia Publishing House, 1934. pp. 589–593, section "The Doctrine of Eternal Election: 2. How Believers are to Consider Their Election, and Engelder, T. E. W., Popular Symbolics. St. Louis: Concordia Publishing House, 1934. pp. 127–128, Part XXXI. "The Election of Grace", paragraph 180. Lutherans believe that all who trust in Jesus alone can be certain of their salvation, for it is in Christ's work and his promises in which their certainty lies.Rom. 8:33, Engelder, T. E. W., Popular Symbolics. St. Louis, Missouri: Concordia Publishing House, 1934. pp. 127–128, Part XXXI. "The Election of Grace", paragraph 179.
However, Lutherans disagree with those that make predestination the source of salvation rather than Christ's suffering, death, and resurrection. Unlike the Reformed (Calvinists), Lutherans do not believe in a predestination to damnation.1 Tim. 2:4, 2 Pet. 3:9, Epitome of the Formula of Concord, Article 11, Election , and Engelder's Popular Symbolics, Part XXXI. The Election of Grace, pp. 124–128. Instead, Lutherans teach eternal damnation is a result of the unbeliever's sins, rejection of the forgiveness of sins, and unbelief, all of which occur when God chooses not to positively intervene during the unbeliever's lifetime.Hos. 13:9, Mueller, J. T., Christian Dogmatics. St. Louis: Concordia Publishing House, 1934. p. 637, section "The Doctrine of the Last Things (Eschatology), part 7. "Eternal Damnation", and Engelder, T.E.W., Popular Symbolics. St. Louis, Missouri: Concordia Publishing House, 1934. pp. 135–136, Part XXXIX. "Eternal Death", paragraph 196. The central final hope of the Christian is "the resurrection of the body and the life everlasting" as confessed in the Apostles' Creed, but Lutherans also teach that, at death, Christian souls are immediately taken into the presence of Jesus in heaven,Luke 23:42-43, 2 Cor. 5:8, Engelder, T. E. W., Popular Symbolics. St. Louis, Missouri: Concordia Publishing House, 1934. p. 130, Part XXXIV. "The State of the Soul in the Interval Between Death and the Resurrection", paragraph 185. where they await this bodily resurrection and the second coming of Jesus on the Last Day.
Reformed
Reformed Christianity (Calvinism) has had controversies over the doctrine of assurance, many however teach that believers may have assurance of their salvation especially through the work of the Holy Spirit and also by looking at the character of their lives. The idea that because good works necessarily result from true faith one can gain assurance by observing evidences of faith in their life is called the practical syllogism. If they believe God's promises and seek to live in accord with God's commands, then their good deeds done in response with a cheerful heart provide proof that can strengthen their assurance of salvation against doubts. This assurance is not, however, a necessary consequence of salvation, and such assurance may be shaken as well as strengthened.
The Westminster Confession of Faith affirmsWestminster Confession of Faith, Chapter 18, paragraph 3 that assurance is attainable though the wait for it may be long:
...infallible assurance doth not so belong to the essence of faith but that a true believer may wait long and conflict with many difficulties before he be partaker of it: yet, being enabled by the Spirit to know the things which are freely given him of God, he may, without extraordinary revelation, in the right use of ordinary means, attain thereunto. And therefore it is the duty of everyone to give all diligence to make his calling and election sure; that thereby his heart may be enlarged in peace and joy in the Holy Ghost, in love and thankfulness to God, and in strength and cheerfulness in the duties of obedience, the proper fruits of this assurance...
Additionally, the Augustinian doctrines of grace regarding predestination are taught in the Reformed churches primarily to assure believers of their salvation since the Calvinist doctrines emphasize that salvation is entirely a sovereign gift of God apart from the recipient's choice, deeds, or feelings (compare perseverance of the saints).
The Marrow Brethren, being a group inside Reformed theology instead taught that assurance is to be grounded upon the gospel, while their opponents emphasized the human element in assurance.
Anabaptism Anabaptists who belong to Conservative Mennonite and New Order Amish communities teach the belief in assurance—"that one can know the state of his soul while on earth". This differs from the Old Order Amish understanding, who teach a "living hope" of salvation. Obedience to Jesus and a careful keeping of the Ten Commandments, in addition to loving one another and being at peace with others are seen as "earmarks of the saved".
Similarities in Catholic teaching