Ephesians 1:14 Which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of his glory.

Earnest is defined as a small quantity given in advance.

Thayers: for the gift of the Holy Spirit, comprising as it does the "powers of the world to come - Hebrews 6:5", is both a foretaste and a pledge of future blessedness.

This earnest is derived from "our inheritance" which is bequeathed to us at regeneration when the adoption occurs (Ephesians 1:4 & 11). The inheritance is eternal life. When bequeathed at adoption, it is reserved for us in immortal heaven, until the redemption of the purchased possession. By faith, we are able to take current possession of eternal life in this present world.

The following passages all refer to this current possession of eternal life.
Matthew 19:16
Mark 10:17
Luke 10:25
Luke 18:18
John 3:15
John 4:36
John 6:54
John 6:68
John 10:28
John 12:25
John 17:2-3
Acts 13:48
Romans 2:7
Romans 5:21
Romans 6:23
1 Timothy 6:12 & 19
Titus 1:2
Titus 3:7
1 John 2:25
1 John 3:15
1 John 5:11
1 John 5:13

Keep in mind that a person cannot recieve the earnest, unless he has first obtained the whole, from which the earnest is derived. In other words, a person can only take a piece of pie from a whole pie.