Holiness-movement and Pentecostal-charismatic teaching that a second, distinct, post-conversion experience of the Holy Spirit is necessary or normative for the believer's mature Christian life. The doctrine takes several forms. (1) Wesleyan entire sanctification: John Wesley's teaching of a second crisis-experience of grace producing perfection-in-love or entire sanctification, distinct from the initial conversion experience. (2) Holiness-movement second blessing: the nineteenth-century Holiness offshoot of Wesleyanism, emphasizing a crisis-experience of complete sanctification (Phoebe Palmer, Charles Finney's later writings, the broader nineteenth-century Holiness movement). (3) Pentecostal baptism in the Holy Spirit: the early-twentieth-century Pentecostal teaching (Azusa Street, 1906, and following) of a second crisis-experience of the Spirit subsequent to conversion, evidenced by speaking in tongues. (4) Charismatic Spirit-filling: the post-1960s charismatic movement's teaching of a second crisis-experience of the Spirit, with various physical-experiential manifestations. The Reformed-confessional position rejects all forms of the second-blessing doctrine. The NT teaching is that every regenerate believer has received the Spirit at the point of conversion (Romans 8:9, if any man have not the Spirit of Christ, he is none of his; 1 Corinthians 12:13, For by one Spirit are we all baptized into one body); the Spirit's ongoing filling and sanctifying work is progressive, integrated with the means of grace, and not constituted by a single post-conversion crisis-experience. The Reformed-confessional doctrine of sanctification (Westminster XIII; Heidelberg Q. 91) presents sanctification as progressive renewal of the whole man by the Spirit's continuing work, not as a second crisis-experience.