An earnest (αρραβων). See 2. Corinthians 1:22 for discussion of αρραβων. Here "of promise" (της επαγγελιας) is added to the Holy Spirit to show that Gentiles are also included in God's promise of salvation.

Of our inheritance (της κληρονομιας ημων). God's gift of the Holy Spirit is the pledge and first payment for the final inheritance in Christ.

Of God's own possession (της περιποιησεως). The word

God's is not in the Greek, but is implied. Late and rare word (from περιποιεω, to make a survival) with the notion of obtaining (1. Thessalonians 5:9; 2. Thessalonians 3:14) and then of preserving (so in the papyri). So in 1. Peter 2:9; Hebrews 10:39, and here. God has purchased us back to himself. The sealing extends (εις) to the redemption and to the glory of God.