"God is the Only Father to All Those Who Have Faith"

Paul, an apostle of Christ Jesus by command of God our Savior and of Christ Jesus our hope,

To Timothy, my true child in the faith: Grace, mercy, and peace from God the Father and Christ Jesus our Lord (1 Timothy 1:1-2).

Paul says Timothy is my true son. He is not ashamed to be called his father. Paul also wants other people to acknowledge that Timothy is his son...We may wonder how this can be consistent with Christ's command, "do not call anyone on earth 'father'" (Matthew 23:9), or with Paul's own assertion, "even though you have ten thousand guardians in Christ, you do not have many fathers, for in Christ Jesus I became your father through the gospel" (1 Corinthians 4:15). I reply by pointing out what Paul says that he is Timothy's father, he does not lessen God's honor in any way, or substitute glory for himself in God's place. Everyone knows that if one thing is subordinate to another, then they are not fighting each other. This is the way that Paul claims to be Timothy's father, while God himself remains Timothy's Father.

God is the only Father to all those who have faith. Through his Word and the power of the Spirit he regenerates all believers. He alone confers faith. He graciously allows ministers to share his honor without losing any of his honor himself.

John Calvin in his commentary on 1 & 2 Timothy & Titus