The Heart of the Gospel

36. All revealed truths derive from the same divine source and are to be believed with the same faith, yet some of them are more important for giving direct expression to the heart of the Gospel. In this basic core, what shines forth is the beauty of the saving love of God made manifest in Jesus Christ who died and rose from the dead. In this sense, the Second Vatican Council explained, "in Catholic doctrine there exists an order or a 'hierarchy' of truths, since they vary in their relation to the foundation of the Christian faith." This holds true as much for the dogmas of faith as for the whole corpus of the Church's teaching, including her moral teaching. 

The Joy of the Gospel, Pope Francis, par. 36, p. 19