"And hope does not disappoint, because the love of God has been poured out into our hearts through the Holy Spirit who has been given to us." (Romans5: 5)
The Navarre Bible Commentary has the following commentary on the above text:
"The love which St. Paul speaks of here, at one and the same time, God's love for us – manifested in his sending the Holy Spirit – and the love which God places in our soul to enable us to love him. The Second Council of Orange, quoting St. Augustine, explains this as follows: "To love God is entirely a gift of God. He, without being loved, loves us and enabled us to love him. We were loved when we were still displeasing to him, so that we might be given something whereby we might please him. So it is that the Spirit of the Father and the Son, whom we love with the Father and the Son, pours charity into our hearts"