I've never read any of the writtings of Karl Rahner. There have been a couple of attempted readings, but nothing I've been able to sustain. For some reason, obviously unsubstantiated,  thought of him as being dry and academic. Recently, though, I picked up a book I've had on the shelf for a while, Karl Rahner Spiritual Writings. This book introduced me to his spiritual side. The few exerpts I've read so far are reminiscent, to me at least, of the Confessions of St. Augustine, thai is, highly personal and introspective.

The following is an offering from his book, Encounters with Silence.

“Draw near to God, and He will draw near to you” (James 4:8). Yet where He is communicating Himself to His creature and embracing it into His love and His praise, He is having the soul recognize how null, how empty, and how weak it is, filled with the nullities of its narrow existence, full of fear at the pain and suffering of the cross, full of petty pride and narrow self-seeking …

But then, in His own time, when it pleases Him, He makes the soul bright, enlightened, so that it longs for a heart of faith, full of sturdy hope, full of love that never ends, so that it longs for a heart that is open and selfless and pure.

Then the Lord fills “His” soul with the power of grace, so that its deeds fulfill the desires and promises of its prayer, so that it becomes strong enough to accomplish all things and endure all a things.

Then HE gives it the Spirit of God, “which comes to help us in our weakness,”

the Spirit that loves it, so that it can forget desires shaped by

the world’s love,

the Spirit that consoles it with His joy,

the Spirit that is the soul’s “first fruits of eternal life.”

Look, that is what a heart is like when it prays. For the person who draws near to God ---

they become one Spirit with HIM. But God’s Spirit is “LOVE, JOY, PATIENCE, KINDNESS, FAITHFULNESS, GENTLENESS, SELF-CONTROL” (Gal. 5:22-23)

That’s what our heart becomes if we pray in the Spirit of God.