Longing for God expresses one's faith, but the absence of God brings the pain of doubt. Faith and doubt, like twin brothers, are inseparable in our faith life.
The groaning of the Holy Spirit is also enlightening, making our foolish hearts wise, making our complicated minds crystal clear, turning our eyes from our circumstance to God himself.
"Rock" usually represents God's salvation in the old testament. Rock is the foundation of a city, salvation is the foundation of one's life.
Jesus replaced the temple as the only way to draw near to God. As long as you are in Christ, God is present.