Christians can’t ever lose the Spirit, but His filling is something we should constantly pursue. This business of sanctification is a lifelong process we are engaged in. Second Corinthians 3:18 says, “We all, who with unveiled faces contemplate the Lord’s glory, are being transformed into his image with ever-increasing glory, which comes from the Lord, who is the Spirit” (TNIV). (See also 2 Thess. 2:13 and Rom. 15:16.)