A sacrament of the New Law in which a baptized person receives the Holy Spirit, is strengthened in grace and signed and sealed as a soldier of Jesus Christ.
Acts 19:5-6 – On hearing this, they were baptized in the name of the Lord Jesus. 6 And when Paul had laid his hands upon them, the Holy Spirit came on them; and they spoke with tongues and prophesied.
Acts 8:14-17 – Now when the apostles at Jerusalem heard that Samaria had received the word of God, they sent to them Peter and John, 15 who came down and prayed for them that they might receive the Holy Spirit; 16 for it had not yet fallen on any of them, but they had only been baptized in the name of the Lord Jesus.
2 Cor. 1:21-22 – But it is God who establishes us with you in Christ, and has commissioned us; 22 he has put his seal upon us and given us his Spirit in our hearts as a guarantee. Eph. 1:13 – you were sealed with the promised Holy Spirit.
Heb. 6:1-2 – Therefore let us leave the elementary doctrine of Christ and go on to maturity, not laying again a foundation of repentance from dead works and of faith toward God, 2 with instruction about ablutions, the laying on of hands, the resurrection of the dead, and eternal judgment.
Tertullian [inter AD 208/212] “The flesh, then, is washed, so that the soul may be made clean. The flesh is anointed, that the soul may be dedicated to holiness. The flesh is signed (with the cross), so that the soul too may be fortified. The flesh is shaded by the imposition of hands, so that the soul too may be illuminated by the Spirit. The flesh feeds on the Body and Blood of Christ, so that the soul too may fatten on God. They cannot, then, be separated in their reward, when they are united in their works” (The Resurrection of the Dead [8, 2).
St. Hippolytus of Rome [AD 204] “Indeed, faith and love prepare oil and cleansing unguents for those who are washed (baptized). But what were these unguents if not the commands of the Holy Word? And what the oil, if not the power of the Holy Spirit? It is with these, after the washing, that believers are anointed as with a sweet-smelling oil. All these things were prefigured through the blessed Susanna for our sakes, so that we of the present time who believe in God, might not regard as strange the things which now are done in the Church, and that we might believe that all of them have been set forth in figures by the patriarchs” (Commentary on Daniel 1, 16). St. Pope Gregory III [AD 731-741] “However, because they were baptized in the name of the Trinity, it is necessary that those indeed who were baptized through a diversity and a variation of the relationship of languages, be strengthened through the hands of imposition and of the holy chrism”. (Baptism and Confirmation, ES 296b)