Having the Holy Spirit

I know that Jesus died for my sins, but I'm worried that I don't actually have the Holy Spirit? How do I know? Can you suggest some Scripture passages that would give me comfort when I am unsure?

From the information you provided with your question, I take it that you not only “know” that Jesus died for your sins but that the Holy Spirit has led you to trust in Jesus Christ as your Savior.  Knowledge of Jesus is one thing, but Spirit-worked faith is what brings into our lives all the blessings Jesus won by his holy life and sacrificial death.

When God brought you to saving faith, he did so through his Holy Spirit, “whom he poured out on us generously through Jesus Christ our Savior” (Titus 3:6).  The Holy Spirit now dwells in you.  Twice in his first letter to the Corinthians the apostle Paul asked a question that reminds Christians that the Holy Spirit lives in them.  “Don’t you know that you yourselves are God’s temple and that God’s Spirit lives in you?”  (1 Corinthians 3:16)  “Do you not know that your body is a temple of the Holy Spirit, who is in you, whom you have received from God?”  (1 Corinthians 6:19)

The same apostle reminds us that the indwelling of the Holy Spirit signifies God’s ownership of us:  “And you also were included in Christ when you heard the word of truth, the gospel of your salvation.  Having 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 possessions—to the praise of his glory” (Ephesians 1:13-14).

Other passages that assure Christians like you that “you have the Holy Spirit” are:

“No one can say, ‘Jesus is Lord,’ except by the Holy Spirit” (1 Corinthians 12:3).

“Now it is God who makes both us and you stand firm in Christ.  He anointed us, set his seal of ownership on us, and put his Spirit in our hearts as a deposit, guaranteeing what is to come” (2 Corinthians 1:21-22).

“Because you are sons, God sent the Spirit of his Son in our hearts, the Spirit who calls out, ‘Abba, Father’” (Galatians 4:6).

“And in him you too are being built together to become a dwelling in which God lives by his Spirit” (Ephesians 2:22).

“Those who obey his commands live in him, and he in them.  And this is how we know that he lives in us:  We know it by the Spirit he gave us” (1 John 3:24).

You have the right idea with your question:  looking to Scripture to find reassurance of God’s love for you and his presence in your life.  God bless your remembrance of passages like these.