There are a number of occasions in the Bible where a person or group of people find themselves confronted with the words, ‘Be strong!’
Now there is at least two ways that these word might be understood.
The first is as an exhortation that is something like, ‘Toughen up, kid!’
The second way is a use something like the words that Jesus used when he spoke to the weak and maimed of his day, ‘Be healed!’ He spoke, and they were healed.
I suggest that in both cases these words, as they occur in the Bible, mean something like, ‘You have no strength and have no way of getting it yourself, but here is the strength you need.’ This is a message for Christians.
For example, in Chapter 10 of the book of Daniel, the prophet-administrator was in a bad way. He had been receiving visions that troubld him greatly. An impressive person came to speak with Daniel as he stood by the river Tigris. Daniel spoke as a person who was near death, as one without any strength. The impressive person said this to him:
“O man greatly beloved, fear not! Peace to you; be strong, yes, be strong!” Daniel 10:19a
As I said before, someone might take these words as an exhortation to toughen up. But Daniel’s reply suggests otherwise. That verse continues like this:
“So when he spoke to me, I was strengthened, and said, Let my Lord speak, for you have strengthened me.” Daniel 10:19b
This is an instance of strengthening that has a similar character to the physical and spiritual healings that the Lord Jesus performed. Daniel didn’t say to the impressive person, ‘Your exhortation has spurred me on’, but rather he reports that at the words of the impressive person, Daniel was given strength that he did not have a moment before. ‘You,’ he said, ‘have strengthened me.’ just as a leper could say of Jesus, ‘He has healed me.’
The strength and resources came from outside of Daniel, not from within. The strength came as a gift of God’s power and love.
In the New Testament, in Ephesians 6, we have very similar words. Paul writes to these Christians and says to them, ‘Be strong’. It is an exhortation, but he doesn’t mean for them to toughen up. The words that immediately follow are: ‘[Be strong] in the Lord and the power of his might’.
Paul is saying, in effect, here is the strength you need; it is the Lord Jesus Christ. His word, His faith, His spirit, His righteousness, His life, death and resurrection on your behalf (the gospel of peace). This is the strength you need. The Christian’s strength is Jesus, the one who long ago completed everything necessary to bring us to God, and the one who sent the Holy Spirit to bring us to new birth. He saved us. His strength achived this. Here is the strength that the weak Christian needs, and He is the only strength that we need.
So, know your strength. This must mean. ‘Know and continually be reminded of who Jesus is and what he has done for you.’