From Saint Albert’s book On Union with God:
Whosoever thou art who longest to enter upon this happy state or seekest to direct thither thy steps, thus it behoveth thee to act.Scientific knowledge is not the same thing as wisdom. Scientific endeavors, for which Saint Albert is justly famous, have no value if they aren’t based ultimately in charity: the love for God and the love for our fellow men. This lack of true charity is common in our skeptical, egotistical age, which so often uses the fruits of the scientific method with evil intent.
First, close, as it were, thine eyes, and bar the doors of thy senses. Suffer not anything to entangle thy soul, nor permit any care or trouble to penetrate within it.
Shake off all earthly things, counting them useless, noxious, and hurtful to thee.
When thou hast done this, enter wholly within thyself, and fix thy gaze upon thy wounded Jesus, and upon Him alone. Strive with all thy powers, unwearyingly, to reach God through Himself, that is, through God made Man, that thou mayest attain to the knowledge of His Divinity through the wounds of His Sacred Humanity.
In all simplicity and confidence abandon thyself and whatever concerns thee without reserve to God's unfailing Providence, according to the teaching of St. Peter: “Casting all your care upon Him,” Who can do all things. And again it is written: “Be nothing solicitous”; “Cast thy care upon the Lord and He shall sustain thee”; “It is good for me to adhere to my God”; “I set the Lord always in my sight”; “I found Him Whom my soul loveth”; and “Now all good things came to me” together with Him. This is the hidden and heavenly treasure, the precious pearl, which is to be preferred before all. This it is that we must seek with humble confidence and untiring effort, yet in silence and peace.
It must be sought with a brave heart, even though its price be the loss of bodily comfort, of esteem, and of honour.
Lacking this, what doth it profit a religious if he “gain the whole world, and suffer the loss of his own soul?” Of what value are the religious state, the holiness of our profession, the shaven head, the outward signs of a life of abnegation, if we lack the spirit of humility and truth, in which Christ dwells by faith and love? St. Luke says: “The kingdom of God,” that is, Christ, “is within you,”
In proportion as the mind is absorbed in the thought and care of the things of this world do we lose the fervour of our devotion, and drift away from the things of Heaven.
The greater, on the other hand, our diligence in withdrawing our powers from the memory, love and thought of that which is inferior in order to fix them upon that which is above, the more perfect will be our prayer, the purer our contemplation. The soul cannot give itself perfectly at the same time to two objects as contrary one to another as light to darkness; for he who lives united to God dwells in the light, he who clings to this world lives in darkness.
The highest perfection, therefore, of man in this life lies in this: that he is so united to God that his soul with all its powers and faculties becomes recollected in Him and is one spirit with Him. Then it remembers naught save God, nor does it relish or understand anything but Him. Then all its affections, united in the delights of love, repose sweetly in the enjoyment of their Creator.
The image of God which is imprinted upon the soul is found in the three powers of the reason, memory, and will. But since these do not perfectly bear the Divine likeness, they have not the same resemblance to God as in the first days of man's creation.
God is the “form” of the soul upon which He must impress His own image, as the seal on the wax or the stamp on the object it marks.
This can only be fully accomplished when the reason is wholly illuminated according to its capacity, by the knowledge of God, the Sovereign Truth; the will entirely devoted to the love of the Supreme Good; the memory absorbed in the contemplation and enjoyment of eternal felicity, and in the sweet repose of so great a happiness.
As the perfect possession of this state constitutes the glory of the Blessed in Heaven, it is clear that in its commencement consists the perfection of this life.
I wrote earlier about Saint Albert and science here.