Is salvation only pardon and assurance?
No. By regeneration, God renews us in righteousness through Jesus Christ, by the power of the Holy Spirit.
Catechism for the Global Methodist Church, question 61
26And I will give you a new heart, and a new spirit I will put within you; I will remove the heart of stone from your flesh and give you a heart of flesh. 27And I will put my Spirit within you and cause you to walk in my statutes and be careful to obey my rules.
14The natural person does not receive the things of the Spirit of God, for they are foolishness to him, and he is not able to understand them because they are spiritually discerned. 15The spiritual person discerns all things, yet he himself is discerned by no one. 16For who has known the mind of the Lord, that he may instruct him? But we have the mind of Christ.
20I live, yet no longer I, but Christ lives in me; and what I now live in the flesh, I live in faith in the Son of God who loved me and gave himself for me.
16I say then: walk by the Spirit, and you will not gratify the desire of the flesh. 17For the flesh desires against the Spirit, and the Spirit against the flesh; for these are opposed to each other, so that you may not do whatever you want. 18But if you are led by the Spirit, you are not under the law. 19The works of the flesh are evident: sexual immorality, impurity, sensuality. 20Idolatry, sorcery, enmities, strife, jealousy, fits of anger, rivalries, dissensions, factions. 21Envyings, drunkenness, carousing, and things like these, of which I forewarn you, just as I forewarned you, that those who practice such things will not inherit the kingdom of God. 22The fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness. 23Gentleness, self-control; against such things there is no law. 24Those who belong to Christ Jesus have crucified the flesh with its passions and desires. 25If we live by the Spirit, let us also keep in step with the Spirit.
1And you, who were dead in your trespasses and sins, 2in which you once walked according to the age of this world, according to the ruler of the authority of the air, the spirit now active in the sons of disobedience, 3among whom we also all once lived in the desires of our flesh, doing the wills of the flesh and of the minds, and we were by nature children of wrath, just as the rest, 4But God, who is rich in mercy, because of the great love with which he loved us, 5and when we were dead in the trespasses, made us alive together with Christ, by grace you are saved
4But when the kindness and the benevolence of God our Savior appeared, 5not by works that we did in righteousness, but according to his own mercy he saved us, through the washing of regeneration and renewal of the Holy Spirit, 6whom he poured out on us richly through Jesus Christ our Savior, 7so that, having been justified by that one's grace, we might become heirs according to the hope of eternal life.
4Through which the precious and very great promises have been granted to us, so that through them you may become participants in the divine nature, having escaped the corruption that is in the world by desire.
Salvation is more than pardon. God forgives, and then God remakes. ΒΆ102 of the Book of Doctrines and Discipline calls this remaking regeneration and describes it as the start of sanctifying grace: "God's sanctifying grace begins with God's work of regeneration, sometimes referred to as 'being born again,' or 'initial sanctification.'" Article IX of the Confession of Faith defines the work itself: "regeneration is the renewal of man in righteousness through Jesus Christ, by the power of the Holy Spirit."
This renewal is a real change inside a person. God promised it through Ezekiel: "I will give you a new heart, and a new spirit I will put within you; I will remove the heart of stone from your flesh and give you a heart of flesh" (Ezekiel 36:26). God also promised to do the work himself: "I will put my spirit within you and cause you to walk in my statutes" (Ezekiel 36:27). Paul describes the same change as it looks to the person who has received it. Those who were "dead in your trespasses and sins" (Ephesians 2:1) have a God (Ephesians 2:4-5).
The renewed life can be seen from the inside. Paul says, "I live, yet no longer I, but Christ lives in me" (Galatians 2:20), and he tells those who belong to Christ to "walk by the Spirit" (Galatians 5:16). The whole change rests on God's mercy: (Titus 3:5-6). The Son and the Spirit work together in this washing, as Article IX teaches. Through God's promises believers "may become participants in the divine nature" (2 Peter 1:4); the next question explains that phrase.
For a Methodist, pardon begins salvation and holiness follows from it. A forgiven person who remained unchanged would have received half of what God offers. The church asks its members to expect the new heart Ezekiel promised, and it points them to prayer, scripture, the Lord's Supper, and Christian fellowship as the ordinary places where the Spirit does that renewing work (Ezekiel 36:27).