What is meant by being “sealed” with the Holy Spirit? The expression occurs here and in Ephesians 4:30, where the present passage is echoed. An owner seals his property with his signet to mark it as his; if at a later time he comes to claim it and his right to it is questioned, his seal is sufficient evidence and puts an end to such questioning. So, the fact that believers are endowed with the Spirit is the token that they belong in a special sense to God. If the twelve disciples of Acts 19:1–7 were among those who heard this epistle read when it reached its destination, they would have thought immediately of that day when Paul met them and told them about the Holy Spirit of whom they had never heard before, the day when they received the Spirit after being baptized into the name of the Lord Jesus and having Paul’s hands laid upon them. And others among their fellow Christians would similarly think of the day when the Spirit came upon them, although to many of them this had happened as soon as they believed, before they entered the baptismal water as the outward and visible sign of the inward and spiritual grace which they had received. One way or the other, they had thus been incorporated into that living fellowship which was inaugurated when the Spirit came down to take possession of the new people of God on the first Christian Pentecost. Other seals, literal or figurative (like circumcision, the seal of the covenant with Abraham), were affixed externally; the seal of the new covenant is imprinted in the believing heart.