But encourage one another daily, as long as it is called “Today,” so that none of you may be hardened by sin’s deceitfulness.
The word translated “encourage” in the NIV might better be translated “exhort” (as in the NRSV) except for the fact that we don’t use that word today. “Warn” (NLT) fits the context, yet might be too strong. And there’s another Greek word which means to warn or instruct. Perhaps a good rendering might be to “strongly encourage.” (See Bill Mounce to consider that word in the New Testament transliterated parakaleo.)
The book of Hebrews was not written to us, but is definitely for us. It was for a group of either Jewish believers, or believers who as Gentiles had previously been God-fearers in Judaism, now under pressure, being persecuted for their faith (at least the beginnings of it), and tempted to go back to Judaism. But no one should think they are signed, sealed and delivered, as to their faith. We need according to the text, daily encouragement, mutual encouragement in our faith (Romans), but also some pointed loving words, to help us stay on track. When we see faith in others which encourages us, we should let them know, so that they might be encouraged by what we see.
The nature of scripture is– what had application for others, now has application for us. We have to consider the writings in their original context, but we must look at it in our setting, circumstances, and situation of life, as well. There has to be a measure of contextualization. But in that process, we have to be careful not to think that their needs were different than ours. At the heart of it, the need is the same. Wherever we find ourselves, or more precisely in this context, others, we need to take this seriously, and apply it to our lives. We need each other in Jesus to help us along, especially through the most difficult and potentially dangerous times. To not turn back, or drift away, but go on in Jesus toward full maturity in him. To the very end.