Lightening during a storm can set a house on fire or destroy circuitry. To prevent this houses are wired so that any electrical surge is routed into the grounded. This process is called grounding.
Grounded can also mean mentally and emotionally stable: admirably sensible ant stable, realistic and unpretentious.
To be "grounded and steadfast in faith and not moved away from the gospel" would mean we rely completely on God to protect us during storms of life. We are not unrealistic to think we will never encounter storm, nor imagine that we are above troubles. We have a realistic outlook, knowing that God will sustain us in all situations (Colossians 1:21-23; Ephesians 3:14-19).
