From the very beginning the life of Blessed Guadalupe Ortiz de Landázuri was filled with God’s gift of faith. The death of her father, the feeling of God's presence that led her to do God's will in Opus Dei with the help of St. Josemaría Escrivá, the apostolate with the citizens of Spain and Mexico to whom she brought the message of Opus Dei – the love for God in everyday life as a way of human fulfilment – it has all made her life a role model for many Christians in seeking God. The fact that she was open to the will of God can be seen in the joy she felt when facing every new challenge, such as going from Mexico to Rome to work at the headquarters of Opus Dei. Heart disease, her faithful companion throughout her whole life, was not only an obstacle in encouraging others to follow Jesus Christ, but also an excellent opportunity to pray, especially for the gifts of faith, hope and love. Since joining Opus Dei, she started regularly writing letters addressed to Saint Josemaría Escrivá, known today as Letters to a Saint. From her first to last steps on this earth she did not give up expressing her soul, as a daughter to a father, through the contents of the letters. These letters, translated into many languages, still encourage people to live a filial relationship with God. In her letters, through various stages and challenges of her life, we can read some spiritual elements such as God's presence, consciousness of being children of God, love of neighbour, love of the Eucharist, supernatural view of difficulties and many other elements important for following Christ in order to be authentic witnesses of Love.