What does Romans 8:27 mean?

Paul has revealed in Romans 8 that the life of a Christian on this side of eternity is one of waiting and longing to be with our God while enduring the suffering of this life. We live with a kind of endless groaning to be made whole by the redemption of our bodies. We are not alone, however. God gives His Spirit to everyone who trusts in Christ (Ephesians 1:13–14; 2 Corinthians 1:22). One way the Spirit helps us in our weakness is by taking our too-deep-for-words groanings, communicating them to the Father as prayers. The Spirit intercedes for us.

Now Paul explains how God receives those prayers. Paul uses a description for God which is both beautiful and perhaps intimidating. Here, he calls God the Father the "one who searches hearts" (Hebrews 4:12–13). The Father and the Spirit are eternally connected. The Father in heaven knows the mind of His Spirit in us. Their connection remains ever unbroken.

The Spirit then forms our unspoken groanings toward God into prayers that conform to God's will. God, ever in search mode, receives those prayers directly from our hearts. In this way, even in our waiting to be with God in person, we are in potentially constant communication with Him.

This does not mean we don't need to pray to God with words. We still need to make an effort to think about what we will say to God before we say it. Intentional prayerfulness is essential for those who are in Christ. This does mean, however, that we don't need to be overly anxious that we're "praying wrong." Because the Spirit is interceding for us to the Father and within His will, we are free to talk to God as little children talk to their fathers. We don't need special language or systems to be sure He is receiving what we're saying. He understands, even better than we do.