1. The “door of faith” (Acts 14:27) is always open for us, ushering us into the life of communion with God and offering entry into his Church. It is possible to cross that threshold when the word of God is proclaimed and the heart allows itself to be shaped by transforming grace. To enter through that door is to set out on a journey that lasts a lifetime. It begins with baptism (cf. Rom 6:4), through which we can address God as Father, and it ends with the passage through death to eternal life, fruit of the resurrection of the Lord Jesus, whose will it was, by the gift of the Holy Spirit, to draw those who believe in him into his own glory (cf. Jn 17:22). To profess faith in the Trinity – Father, Son and Holy Spirit – is to believe in one God who is Love (cf. 1 Jn 4:8): the Father, who in the fullness of time sent his Son for our salvation; Jesus Christ, who in the mystery of his death and resurrection redeemed the world; the Holy Spirit, who leads the Church across the centuries as we await the Lord’s glorious return.
10 [...] "Man believes with his heart and so is justified, and he confesses with his lips and so is saved” (Rom 10:10). The heart indicates that the first act by which one comes to faith is God’s gift and the action of grace which acts and transforms the person deep within.
The example of Lydia is particularly eloquent in this regard. Saint Luke recounts that, while he was at Philippi, Paul went on the Sabbath to proclaim the Gospel to some women; among them was Lydia and “the Lord opened her heart to give heed to what was said by Paul” (Acts 16:14). There is an important meaning contained within this expression. Saint Luke teaches that knowing the content to be believed is not sufficient unless the heart, the authentic sacred space within the person, is opened by grace that allows the eyes to see below the surface and to understand that what has been proclaimed is the word of God.
Confessing with the lips indicates in turn that faith implies public testimony and commitment. A Christian may never think of belief as a private act. Faith is choosing to stand with the Lord so as to live with him. This “standing with him” points towards an understanding of the reasons for believing. Faith, precisely because it is a free act, also demands social responsibility for what one believes. The Church on the day of Pentecost demonstrates with utter clarity this public dimension of believing and proclaiming one’s faith fearlessly to every person. It is the gift of the Holy Spirit that makes us fit for mission and strengthens our witness, making it frank and courageous.
Profession of faith is an act both personal and communitarian. It is the Church that is the primary subject of faith.
[Pope Benedict, motu proprio Porta Fidei]
