His presence is his garantee
Eph 1:14
14 (1)His presence within us is God's guarantee that he really will give us all that he promised; and(2)the Spirit's seal upon us means that God has already purchased us and that he guarantees to bring us to himself. This is just one more reason for us to praise our glorious God.
(TLB)
Eph 1:3-15
3 Praise be to the God and Father of our Lord Jesus Christ, who has blessed us in the heavenly realms with every spiritual blessing in Christ.
4 For he chose us in him before the creation of the world to be holy and blameless in his sight. In love
5 he predestined us to be adopted as his sons through Jesus Christ, in accordance with his pleasure and will--
6 to the praise of his glorious grace, which he has freely given us in the One he loves.
7 In him we have redemption through his blood, the forgiveness of sins, in accordance with the riches of God's grace
8 that he lavished on us with all wisdom and understanding.
9 And he made known to us the mystery of his will according to his good pleasure, which he purposed in Christ,
10 to be put into effect when the times will have reached their fulfillment-- to bring all things in heaven and on earth together under one head, even Christ.
11 In him we were also chosen, having been predestined according to the plan of him who works out everything in conformity with the purpose of his will,
12 in order that we, who were the first to hope in Christ, might be for the praise of his glory.
13 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,
14 who is a deposit guaranteeing our inheritance until the redemption of those who are God's possession-- to the praise of his glory.
15 For this reason, ever since I heard about your faith in the Lord Jesus and your love for all the saints,
(NIV)
2 Cor 1:22
22 Who hath also sealed us, and given the earnest of the Spirit in our hearts. (KJV)
2 Cor 5:5
5 Now he that hath wrought us for the selfsame thing is God, who also hath given unto us the earnest of the Spirit. (KJV)
*Ps 86:17
17 Shew me a token for good; that they which hate me may see it, and be ashamed: because thou, LORD, hast holpen me, and comforted me. (KJV)(Eph 2:7 And now God can always point to us as examples of how very, very rich his kindness is, as shown in all he has done for us through Jesus Christ.(TLB)
4972 sphragizo-to set a seal upon, to mark with a seal, to seal
a) for security: from Satan
b) since things sealed up are concealed (as the contents of a letter), to hide, keep in silence, keep secret
c) in order to mark a person or a thing
1) to set a mark upon by the impress of a seal or a stamp
2) angels are said to be sealed by God
d) in order to prove, to confirm, or to attest a thing, to confirm authenticate, to place beyond doubt
1) used of a written document
2) to prove one's testimony to a person that he is what he professes to be
4972 sphragizo (sfrag-id'-zo);
from 4973; to stamp (with a signet or private mark) for security or preservation (literally or figuratively); by implication, to keep secret, to attest:
KJV-- (set a, set to) seal up, stop.