NT.filter - web firmly:

web@1Corinthians:15:2 @by which also you are saved, if you hold firmly the word which I preached to you--unless you believed in vain.

web@Colossians:2:19 @ 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.

web@1Thessalonians:5:21 @Test all things, and hold firmly that which is good.