8 Therefore said the Lord, “Who has power to slay both body and soul in hell-fire.” How? When the ungodly shall be cast into hell-fire, will his body and his soul burn there? Everlasting punishment will be the death of the body; the absence of God will be the death of the soul. Would you know what the death of the soul is? Understand the Prophet who says, “Let the ungodly be taken away, that he may not see the glory of the Lord.” Let the soul then fear its proper death, and not fear the death of its body. Because if it fear its own death, and so live in its God, by not offending and thrusting Him away from him, it will be found worthy to receive its body again at the end; not unto everlasting punishment, as the ungodly, but unto life eternal, as the righteous. By fearing this death, and loving that life, did the Martyrs, in hope of the promises of God, and in contempt of the threats of persecutors, attain themselves to be crowned with God, and have left to us the celebration of these solemnities.
Source: Sermons on Selected Lessons of the New Testament (New Advent)