Treasury of Scripture Knowledge
2 Corinthians 1:22
He has placed His seal of ownership upon us by giving us the down payment of the Holy Spirit [to live] in our hearts.
And not just the world, but even we [Christians] ourselves, who have the firstfruits of the Holy Spirit [i.e., the first installment of our inheritance from God] also groan within us, eagerly waiting to be adopted as [God's] children, and receive back our bodies [i.e., in the resurrection].
You [Gentiles] also, who are in Christ, after having heard the message of truth, the good news about your salvation, and [after] believing in Him, were sealed [i.e., as evidence of ownership] with the promised Holy Spirit. [or, "the Holy Spirit who brings promises"].
And do not grieve God's Holy Spirit by whom you were sealed [i.e., given evidence of God's ownership] until the day of redemption [i.e., until you receive your new body in heaven. See 1:14].
1 John 3:24
And God lives in the heart of the person who [continually] obeys His commands, and he lives in [fellowship with] God. And here is [another] way we know that God lives in our hearts: It is by [means of] the Holy Spirit, whom God gave to us. [See Rom. 8:9, 11; James 4:5; I Cor. 6:19].