What is the indwelling Holy Spirit the down payment of?
The indwelling Holy Spirit is the earnest, or down payment, of the believer’s inheritance as a joint heir with Christ. He guarantees that the salvation transaction will be completed and holds it until the redemption of the purchased possession. This indwelling sealing confirms the promised inheritance.
Les explains from Ephesians 1:13-14 that after a person heard the word of truth, the Gospel of salvation, and believed, they were sealed with the Holy Spirit of promise. That sealing is part of the salvation experience; the Spirit marks the believer. Verse 14 calls Him the earnest, a down payment sufficient to make sure the transaction is completed. So the indwelling Holy Spirit is the down payment of our inheritance, which we will have as joint heirs with Christ, and He holds it until the redemption of the purchased possession. Les notes that soul and spirit are redeemed in full, but the body is what is left and awaits redemption.
Which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of his glory.