1°) Follow the Church Enlightened by God’s Spirit
"Hence there exists a close connection and communication between sacred tradition and Sacred Scripture. (…)
It is not from Sacred Scripture alone that the Church draws her certainty about everything which has been revealed. (…)
The task of authentically interpreting the Word of God, whether written or handed on, has been entrusted exclusively to the living teaching office of the Church (…)
Sacred tradition, Sacred Scripture and the teaching authority of the Church, in accord with God's most wise design, are so linked and joined together that one cannot stand without the others."
(Excerpts from § 9 and 10 of "Dei Verbum", Vatican II)
2°) Read « with the same Spirit that caused it to be written", the Holy Spirit
To read Sacred Scripture then, it is necessary to read "with the same Spirit that caused it to be written", the Holy Spirit: "For the correct understanding of what the sacred author wanted to assert, due attention must be paid to the customary and characteristic styles of feeling, speaking and narrating which prevailed at the time of the sacred writer, and to the patterns men normally employed at that period in their everyday dealings with one another.
But, since Holy Scripture must be read and interpreted in the sacred spirit in which it was written, no less serious attention must be given to the content and unity of the whole of Scripture if the meaning of the sacred texts is to be correctly worked out. The living tradition of the whole Church must be taken into account along with the harmony which exists between elements of the faith.
It is the task of exegetes to work according to these rules toward a better understanding and explanation of the meaning of Sacred Scripture, so that through preparatory study the judgment of the Church may mature. For all of what has been said about the way of interpreting Scripture is subject finally to the judgment of the Church, which carries out the divine commission and ministry of guarding and interpreting the Word of God."
(Excerpts from § 12 of Dei Verbum, Vatican II)