Been doing a lot of prayer and meditation on Psalm 91 - on the surface it would seem to be a Psalm about the protection of God, but layered, it appears to be a Psalm about salvation and deliverance.
Psalm 91:1 talks about the "secret place" of the Most High, which sounds to me like your prayer closet, where God who sees in secret rewards you openly (Matthew 6:4). It goes on to say they shall "abide" under the shadow of the Almighty. "Abiding" in God is praying and living IN Him. Therefore, I believe the opening of this Psalm is telling us the protection a healthy prayer life gives us. It is from the prayer closet that the rest of the Psalm springs.
91:2 - God is your refuge and fortress; you'll trust in Him -- This is the by-product of a healthy prayer life. Only one who prays can have the confidence to say God is their "refuge and fortress". It is only through answered prayer you come to fully trust Him. This is also the cry of a mature Christian. When adversity strikes, less mature Christians blame God for their problems, but a mature Christian finds their refuge in Him against the storms of life.
91:3 - While it seems to be talking about the snare (trap) and pestilence (disease) that comes upon the wicked, what if the "snare" is worldly lies and the "pestilence" is doubts and fears that eat away at our beliefs? Perhaps this is a metaphor for Satan and sin. Who alone delivers us from the snare of the "fowler" (Satan)? From the "deadly" pestilence (sin)? Yeshua.
91:4 - His truth is our shield - in Eph. 6:16, Paul says our shield is FAITH. Therefore, 100% trust in His truth is our shield, which we can only keep believing when we pray. I find it interesting that in Yeshua's High Priestly Prayer, He says, "Sanctify them in Thy Truth. Thy Word is Truth." (John 17:17) Therefore, if God's Truth is our shield, it is also the Word of God, from Yeshua's Own mouth. We must be ever-diligent to keep our heads bowed in prayer and our noses in Scripture.
91:5 - Be not afraid of terror by night/arrow flieth by day - Faith is the absence of fear -- "terror by night" could be demonic oppression (if you've had horrible dreams from time to time) and the arrow by day could be the fiery darts of the enemy while you walk out your life for God. But perfect love casts out fear (1 John 4:18). There is now no more condemnation for those who are in Christ Jesus (Romans 8:1).
91:6 - Pestilence that WALKETH in the darkness, destruction at noonday - sounds like spiritual warfare to me. "Walketh" assumes intelligence, "darkness" assumes the absence of Light, knowledge, understanding. Also, if pestilence refers to sin as in the previous verse 3, sins usually happen alone, in the dark. However the destruction at noonday is interesting wording, because it assumes the destruction happens in the Light. Perhaps this signifies backsliding of the Christian.
91:7-8 - Thousands fall at your side, only with thine eyes shalt thou behold reward of wicked -- DEATH will not harm you. This isn't speaking of death in the flesh, but death of the soul. Since you are saved by Yeshua's sacrifice on the cross, you will not participate in the second death, but only see it sentenced to others.
91:9-10 - Because you make God your habitation, no evil or plague comes near your dwelling - Living in GOD makes Him your Fortress. That means "your dwelling" would be GOD Himself. Evil has no sway over a child of God, nor will any of God's wrath be meted to you. Also, making God your habitation assumes you visit with Him every single day. This is no casual relationship with the Almighty.
91:11-12 - He gives His angels charge over thee -- We have angelic protection! Again, a healthy prayer life dispatches angels just as a general calls for back-up in wartime. The fascinating thing about this promise is it's a by-product of fully trusting in God and making our habitation in Him. God is our fortress, therefore, He makes sure we are protected when we leave our homes, whether or not we ask Him to.
91:13 - Thou shalt tread upon the lion, adder, dragon under thy feet - Christ gives us amazing authority! The enemy is under OUR feet because as His Body, we ARE His feet! The lion (1 Peter 5:8), the adder (Genesis 3:4), and the dragon (Revelation 12:3) - if you'll notice, these are all pictures of Satan. In my opinion, this gives us three "witnesses" to the fact that Satan has no authority over us whatsoever.
Then, God's promise to the believer:
91:14 - I will set Him on high because he hath known My name -- This verse assumes that by knowing God's name, we know Him. Obviously not everyone who knows the name of God knows God, however, in this context, I believe it means knowing that God's promises are true because He swears upon His name. When we rest in the promises of God and have full confidence in His character, we can say we "know God's name". He sets us "on high" for this, and blesses us in our endeavors. Because we look toward Heavenly things, the trials of earth are "small" in comparison. Also, when we know Who God is and trust in His name, we will be allowed entrance into Heaven, as all who call upon the name of the Lord shall be saved (Acts 2:21).
91:15 - He calls upon Me and I will answer, I will be with him in trouble - Again, we see the fruit of a healthy prayer life. God answers His friends. Notice He doesn't keep one OUT of trouble, but will be WITH him in trouble. Psalm 91 isn't about keeping one FROM the evil of the world, but showing that walking with God is HOW to get through the evil of the world. But the amazing thing about this promise is the fact that when we make God our abode, He answers our prayer. We love on Him, He loves on us. A beautiful exchange.
91:16 - Satisfies with long life, show My salvation - God has regularly promised long life to those who obey Him. Here, God promises to the one who calls upon Him (in verse 15) that He will show His salvation. Again, everyone who calls upon the name of the Lord shall be saved (Romans 10:13). This doesn't necessarily mean that God will keep us unto old age. There are plenty of people who love the Lord who go home to Heaven at a relatively young age. That's why I believe by showing us His salvation, He thereby grants "long life" throughout eternity.
It was from this Psalm the devil tempted Yeshua to throw Himself from the top of the temple as "angels will keep charge over thee lest thee dash thy foot against a stone." Christ responded by, "You shall not tempt the Lord thy God." ~Matthew 4:5-7 Interesting, isn't it, how Satan twists Scripture to tempt us? That is why it is SO VERY IMPORTANT we have a strong prayer life and "Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth." ~2 Tim. 2:15. If we do not pray and study, we are sitting ducks for the devil to run roughshod right over us. But if we resist the devil, he will flee from us (James 4:7).
While Psalm 91 offers support, protection, and comfort to the hurting, weary soul, we must also understand that the promises of God come about by making Him our fortress, our habitation, and abiding in the secret place under the shadow of His wings - our prayer closets. God doesn't want casual relationships, He wants to be the reason our hearts beat - He wants us to live within Him every single day. He also wants us to dwell within His Truth, which Yeshua told us was God's Word. If we dwell within the Word of God, we come to know the mind of Christ (1 Corinthians 2:16).
The wonderful thing about dwelling within the Word of God is that the written Word gives us more faith, more hope, and more LOVE for the Living Word, Adonai Yeshua. Praise the Lord.