Knowing what they deserve, the Israelites should fear God. Knowing what we deserve, we should fear God. Thankfully, for the sake of His glory, He is willing to save and to restore, and so we have no need to fear when we have Him as our Lord and Saviour.
When you pass through the waters, I will be with you; and through the rivers, they shall not overwhelm you; when you walk through fire you shall not be burned, and the flame shall not consume you. Isaiah 43:2
Does this mean nothing bad will ever happen to God's people. No, of course not. Jesus promised us that in this world we would have trouble. We need to be careful not to take verses out of context and claim them for our own personal situation when that's not the correct application of the verse.
My ESV Study Bible has this notation for this verse....
"YOU" designates the whole people (v1). Even when they are subject to the hardships of captivity and exile, God is still with his people
Not only has He promised to be with His people, but He will also preserve a remnant - for the sake of His glory.
That verse was specific to the Israelites, but we can also take something from it. He will always be with us, and there will always have a remnant of believers. And ultimately, though our earthly bodies can be destroyed, no one can destroy our eternity with Him.
Jesus came to earth for a purpose: to live a perfect life, to die in our place as a sacrifice for our sins, and to rise from the dead displaying God's victory and power over sin and death. His death did not take Him by surprise. And we see, beginning in this passage, how He very deliberately goes to Jerusalem at Passover time, to become our true Passover Lamb.
We also see an example of the soils parable from a couple weeks back, play out for us here. Many people were praising Him and shouting "Hosanna" now when they thought He would save them the way they wanted Him to, but after His death we will see that the number of true believers was small indeed. People sometimes claim belief, when really they want Jesus for what He can do for them and they don't truly understand His gospel message. A genuine believer does not fall away - eternal life lasts forever and begins at the moment of salvation. Someone who turns away from Jesus only proves that their initial profession of belief was not genuine (I John 2:19, ). Genuine believers do sometimes have times of doubting or even backsliding, but a true believer will persevere to the end.
Tomorrow's Bible In a Year Passage passage: Isaiah 45-46, Mark 11:19-33