The Greek adjective anexichniastos means unsearchable, unable to be tracked, or beyond tracing out. Occurring twice in the NT (Romans 11:33; Ephesians 3:8), it describes the unfathomable depths of God's ways and the inexhaustible riches of Christ.
Anexichniastos is a word of theological awe. Paul uses it at the climax of his great argument about election and salvation (Romans 9–11): 'How unsearchable his judgments, and his paths beyond tracing out!' (11:33). It is also applied to Christ's riches (Ephesians 3:8) — the inexhaustible wealth of knowing Christ that Paul was commissioned to preach. This word guards against the human tendency to reduce God to our comprehension. He is always more than our theology — always ahead of our pursuit, always deeper than our diving.