In John 14:26, Jesus says, "But the Helper, the Holy Spirit, whom the Father will send in my name, he will teach you all things and bring to your remembrance all that I have said to you."
Can you imagine what the Christian life would be like without the Holy Spirit? What would it be like going through all the hardships this life has to offer without His encouragement and guidance? We couldn't handle them. We should be exceedingly grateful that God cared about us enough to send His Spirit.
The Holy Spirit helps us understand the meaning of Scripture, Plus, He brings it to mind when we need it the most. Still, this doesn't mean we're going to automatically understand all of Scripture—or even most of it. We must read, study, and seek to memorize God's Word.
In 2 Peter 1:16, the writer says, "For we did not follow cleverly devised tales when we made known to you the power and coming of our Lord Jesus Christ, but we were eyewitnesses of His majesty."
And Paul tells us in 2 Timothy 3:16-17, "All Scripture is inspired by God and profitable for teaching, for reproof, for correction, for training in righteousness; so that the man of God may be adequate, equipped for every good work."
We can understand and remember the passages we study because of the indwelling Holy Spirit. We can also experience peace because of His presence.
In John 14:27, Jesus says, "Peace I leave with you; My peace I give to you; not as the world gives do I give to you. Do not let your heart be troubled, nor let it be fearful."
If we obey the command to not let our hearts be troubled, we will experience peace.
How? If we put our faith, hope, and trust in Christ as Savior and Lord, we experience eternal peace with God.
Our salvation is secure for all eternity. Because of His indwelling presence, we enjoy the peace of God in the midst of life's difficult situations.
We experience the peace of God by trusting in His sovereignty in all things, especially in times of trouble. We are commanded not to let our emotions get the best of us. "Let not …" We can also experience peace with others.
Ephesians 2:14 says, "For he himself is our peace, who has made us both one and has broken down in his flesh the dividing wall of hostility."
The wall Jesus broke down was the wall between Jews and Gentiles, who at one time were enemies. In fact, there was a literal wall in the temple that divided the Jews from the Gentiles. So, even the Gentiles who were gathered to worship the One True God were separated from the Jews. Because of Christ the division is gone.
This applies not only to people groups but also to individuals. We can have peace with one another by working on our differences and misunderstandings. It's really easy to say, "That person just isn't listening. I don't want to have anything to do with them. So, I'm going to switch Sunday School classes." Or "I'm going to leave this church because I don't get along with him or her."
That's not peace. Christ gave us the ability to work through our differences and labor together for the gospel. Because of Christ, we can go to one another, humbly ask forgiveness, and be reconciled. We can have peace with one another. When we pursue Christ through His Word and build up one another, we experience the peace of Christ (Romans 14:19).
Jesus had peace in His heart for what was coming. He was going to the cross to endure physical and emotional pain—and spiritual torment. Yet, He went to Gethsemane with peace in His heart. He knew what He was doing was the Father's will. If you know you're being obedient to God's Word, you can stand firm, having the peace of Christ in your heart during hard times.
In order to obey the Lord's command to not let our hearts be troubled, we must believe more thoroughly, trust more entirely, rest more unreservedly, hold more firmly to Christ, and let go of ourselves more freely. We must put all our faith, hope, and trust in Christ and His Word.
Jesus, recognizing how troubled our hearts can get during the trials of life, said He was not only the solution to our troubled heart but also the provider of all we need. We can experience His comfort in seven ways.
Faith is the foundation of true comfort. Faith allows us to overcome our sin and causes us to remember what Christ has done for us on the cross (Romans 5:8). It causes us to remember that Jesus will never leave us nor forsake us (Deuteronomy 31:6). Having faith in Christ and remembering what He's done for us provides us comfort.
Hope in Christ is the comfort and anchor of the soul (Colossians 1:27; 1 Timothy 1:1; Hebrews 6:19-20). If we're without Christ, we're without hope (Ephesians 2:12). Instead, because of Christ, we know when He returns, or He takes us home, we'll be with Him. We will be in the presence of our Lord, our God, our Savior. This hope gives us great comfort in times of trials.
Jesus is our advocate with the Father, and He's the unique revealer of the Father. He sent the Holy Spirit to aid us in understanding Him, guiding us into all truth and to reveal the mystery of the Christ (1 John 2:1). Having a deeper understanding of Christ and His glory provides us comfort.
Because of Jesus and through Jesus you can take pray, taking all your hurt, sorrow, pain, grief, questions, issues, frustrations, and uncertainties, and bring them into the very presence of the God who spoke the universe into existence. This gives us great comfort, that we can go to God about anything, for any reason, at any time. He is truly God with us. (Luke 18:1; 1 Thessalonians 5:17; James 5:16)
I can't imagine a greater comfort than knowing that God loves me. He loved us before we ever loved Him because, while we were still slaves to our sin, Christ died for us (Romans 5:8), and there is nothing that can separate us from His love (Romans 8:38), and His love endures forever (Psalm 136).
The Holy Spirit
We're comforted by God through the Holy Spirit. He teaches us, guides us, convicts us of sin, calls us to repent, so we can pursue a life of godliness (2 Peter 1:3). And He also equips us for every good work (2 Timothy 3:16-17).
Those who have put their faith, hope, and trust in Christ as Savior and Lord can experience the direct opposite of trouble. They can experience His peace (Romans 5:1), which surpasses all understanding (Philippians 4:7). 
It's sad when we go through hard times and forget what Christ has done for us on the cross and we worry about our circumstances. We feel like all hope is lost. When we try to understand what's going on in our own strength, we feel defeated. We might pray, but it's not out of love. It's out of hurt, anger, and frustration. We forget that God loves us. We forget that He sent His Helper. And when we get caught up in our circumstances and try to handle things on our own, we lose out on experiencing the peace of Christ.
But when we trust the cross of Christ, when we trust His righteousness, His power, His sovereignty, and His Word, we experience comfort from the Spirit and peace from Christ.