The Apostle asks in prayer that their love may abound in knowledge and in all perception. Love is the active power of Christian life, embracing both heaven and earth.
It is poured into Christian hearts together with the reception of the grace of the Holy Spirit, and immediately begins to move them toward corresponding works. The further one goes, the more works there are. But the more works there are, the warmer love becomes.
The measure of love is infinity. See St. Chrysostom. Thus, by the natural course of Christian life, it abounds in Christians.
St. Paul wishes that love, while abounding in itself, may also abound in understanding, εν επιγνωσει, that is, in knowledge. This is how he expressed it.
His thought is this: I pray that you may abound not only in love, but also in knowledge. Love needs the light of knowledge, so that it may be "with discernment and reflection. There are some who love irrationally" (St. Chrysostom).
Knowledge here embraces all Christian understanding. Its object is not only the commandments, but also all dogmas and all other subjects touching Christianity.
Only knowledge of everything properly illumines all the paths of life and protects the active power of love from wrongful deviations. The Creed already gives the outline of the whole domain of Christian knowledge.
A life of reflection and inward attention, with the word of God and all-enlightening grace, develops each point of it into a whole system. Finally, the whole of it is formed distinctly in the mind, with due detail.
Embrace all of this, and you will see that here is an inexhaustible source of light. When this is attained, reason becomes not only enlightened, but light-bearing.
This is what St. Paul wishes for the Philippians in wishing that they abound in understanding. Yet even this is not enough. It is also necessary to abound in perception, εν αισυησει.
The external senses are also called by this word. But St. Paul plainly means spiritual perception. The external senses test things and make their qualities known.
In the same way, spiritual perception within its own sphere tests spiritual things and determines their qualities. Both there and here, the distinctive property of perception is touching and tasting.
The multiplication of experiences by the external senses gives external experience. The multiplication of touchings and tastings of spiritual things gives spiritual experience.
This is the abundance St. Paul wishes for the Philippians when he prays for their abounding in perception. Elsewhere he expressed this perfection as having senses trained to discern good and evil.
Here are all the sides of Christian perfection. Love is the moving power. Knowledge is the illumination of the path. Perception is the skill of knowing how and where to step on the path. Nothing greater can be wished.