Marked with a Seal
Eph 1:13,14 And you also were included in Christ when you heard the word of truth, the gospel of your salvation. Having believed, you were marked in him with a seal, the promised Holy Spirit, who is a deposit guaranteeing our inheritance until the redemption of those who are God’s possession-- to the praise of his glory.
Here is the order of salvation. First you have to hear, then believe, then you receive the Holy Spirit. We saw this worked out in the Pentecost of Acts 2. Peter preached the message. Those who believed were baptized received the Holy Spirit.
The receiving of the Holy Spirit is a one time event. This is the "baptism of the Holy Spirit" that John the Baptist refers to "I baptize you with water, but he will baptize you with the Holy Spirit." Mark 1:8 It is also what makes one born of God. "Yet to all who received him, to those who believed in his name, he gave the right to become children of God-- children born not of natural descent, nor of human decision or a husband's will, but born of God." John 1:12 It takes no effort on the person's part to be born of God. Having believed in Christ, one is automatically born of God by the Holy Spirit. And that is also what it means to be born again. "I tell you the truth, no one can enter the kingdom of God unless he is born of water and the Spirit. Flesh gives birth to flesh, but the Spirit gives birth to spirit. You should not be surprised at my saying, 'You must be born again.' The wind blows wherever it pleases. You hear its sound, but you cannot tell where it comes from or where it is going. So it is with everyone born of the Spirit." John 3:5-8
There are many implications and aspects of being born of the Spirit, but in particular here Paul points out the aspect of being marked out in a special category for a particular destiny, which has been his emphasis throughout this chapter. Officials used official seals to indicate the authority or authenticity of a document. What is the mark of the Christian? It is the effects that the Holy Spirit has on one's behavior, as John writes in 1John 3:9,10 mentioned previously in the comment on verse 5.
So one aspect of a seal is as an identifying mark. But another aspect is in the sense of being a guarantee. Today when you buy a product, it may come with a guarantee associated with a seal. But if you don't have that seal, then neither do you have a guarantee. Since salvation is eternally secure and unloseable, the Christian only need be concerned whether he has obtained it. If a person has put salvific faith in Christ, such a person is then born of God, and the evidence of his regeneration will be revealed in his lifestyle and attitudes. These are the effects of the Holy Spirit. If a person sees these effects in their life, they can be assured of their salvation. But if not, then they should take heed to Paul's warning to the Corinthians "Examine yourselves to see whether you are in the faith; test yourselves. Do you not realize that Christ Jesus is in you-- unless, of course, you fail the test?" 2Cor 13:5
The inheritance is in the future. It is the future hope of becoming sinlessly perfect, like Christ and entering into God's presence blameless with great joy experiencing intimacy with Christ and being revealed as a son of God, not to mention the rewards for Christian services rendered in this life.
<