Can we content ourselves with such an unreal faith in Christ, as in no sufficient measure includes self-abasement, or thankfulness, or the desire or effort to be holy?
For how can we truly feel our need of his help, or our dependence on him, or the nature of his gift to us, unless we know ourselves?
How can we in any sense be said to have that “mind of Christ”, to which the Apostle exhorts us, if we cannot follow him to the height above, or the depth beneath; if we do not in some measure discern the cause and meaning of his sorrows, but regard the world, and man, and the system of Providence, in a light different from that which his words and acts supply?
Obedience to God’s commandments, which implies knowledge of sin and of holiness, and the desire and endeavour to please him, this is the only practical interpreter of Scripture.
Without self-knowledge you have no root in yourselves personally; you may endure for a time, but under affliction and persecution your faith will not last.
This is why many in this age (and every age) become “atheists”, heretics, schismatics, disloyal despisers of the Church.
They cast off the form of truth, because it never has been to them more than a form.
They endure not, because they never have tasted that the Lord is gracious; and they never have had experience of his true power and love, because they never got to know themselves properly, never known their own weakness and need.
– Bl. John Henry Newman [title added]