Firstly: It is necessary to grasp that Roman Catholics, via the age old teachings of their Church, are not bound by bible alone nor by faith alone nor by grace alone teachings.. as some other Christians are.
While these three mentioned methods of living are each an important part of their overall concept of what The Father In Heaven expects of His children, Catholics also take into account the concept of Tradition.
It is easiest to say that: they attempt to live within dogmatic parameters which include:
1). Firstly Scripture, and an interpretation of Scripture, which is for the betterment of a Universal Teaching and Liturgy.
1a). Liturgies remaining open to change and designed for the delivery of the grace attainable by the Word and grace attainable through those Sacraments believed to be the vessels that actually contain the Grace that they imply.
a1). That Jesus Himself instituted the Sacraments as such and the Biblical recordings of same, along with the observations of Graces received by recipients over time, are the justification.
a2). It is very important to research – study – and know the historical and spiritual truth that: The Bible itself is the culmination of Divinely Inspired Writings, given to mankind throughout “time” and agreed upon by mankind in around the year 400 AD by those whom, up until that time, got their learning from studying Hebrew Scripture (including the Old Testament), as well as faith, grace, tradition past to them, by those that learned, from the original 12 Apostles.
The Original 12 were taught by Jesus Himself, although were NOT confirmed in that teaching until The Third Person of the Trinity did so at Pentecost, and each generation of “Ordained Successor” after that was given the earthly authority in heavenly matters via the Laying on of the Hands.
These 4th-5th century persons, through 400 years worth of Apostolic Succession, (which is spoken of in each century, in many of their writings to each other) possessed the power of The Holy Spirit to Bind and Loose.
Then realize that they did this binding when agreeing on which Writings were Divinely Inspired “enough” to be included within the Cannon (for the Liturgy) and what we know today as The Bible.
1b). These things are the seed which has grown into Tradition by being a culmination of inspirations – pondering – discernment – and rulings by some of the greatest thinkers of each age, for roughly 2000 years.
2). Secondly, yet equally, Roman Catholics are guided by this, ancient yet ongoing, Tradition. This Tradition itself is a Holy Responsibility that is guided by and relying on the freedom of each member, of the Church, to make judgments and question the teachings of their church. NOT an invitation to BREAK THE RULES. Although through any members personal revelation, perceived to be received from GOD via: Divine inner locution during prayer or Scripture interpretations or apparitions and the likes, are invited to raise issues.
2a). They fully believe that God has never stopped and will not stop communicating with mere earthlings via sending messages .and messengers….most of which are very personal and meant for the receiver alone but others are meant for the overall good of the membership.
2b). Roman Catholics are encouraged to weigh, with the caution of Discernment, those messages they receive as to whether personal or for the good of all. Then bring any that are appropriate to the attention of a legitimate authority within the Church.
b1). To which change is inevitable and adding to the wealth of knowledge of Gods Kingdom. And the means of attaining change can be enhanced for the individual immediately and or for the good of all throughout time.
b2). Change within the teachings and even the dogma (new dogmatic declarations being added that is) has always come about by all members of this body remaining open, firstly, to direct revelation from God, and, secondly, to the rulings of the hierarchy and authority they acknowledge as the Lords Vicar.
Additional Personal observation: When some episodes of the Old Testament Writings are read, like that 40 years wondering in the desert one, as well as many others, including the 1000s of writings “considered” for inclusion in the New Testament, it seems as though God has never been in a big hurry in some of these matters. This in itself is a loving grace allowing both individuals of each century and all of mankind extra time to ponder and discern.