“You also were included in Christ when you heard the word of truth, the gospel of your salvation. When you 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.”
– Ephesians 1:13-14.

God deposited His Spirit in us. How do you invest in the Spirit to guarantee that inheritance?