'Firmly' in the Bible

However, you must remain firmly established and steadfast in the faith, without being moved from the hope of the gospel that you heard, which has been proclaimed to every creature under heaven and of which I, Paul, have become a servant.

having been firmly rooted and now being built up in Him and established in your faith, just as you were instructed, and overflowing with gratitude.

and not holding firmly to the Head, from whom all the body, being supplied and knit together through the joints and ligaments, grows with God's growth.