How to have a peaceful heart & mind?

Philippians 4:4-8 NKJV
[4] Rejoice in the Lord always. Again I will say, rejoice! [5] Let your gentleness be known to all men. The Lord is at hand. [6] Be anxious for nothing, but in everything by prayer and supplication, with thanksgiving, let your requests be made known to God; [7] and the peace of God, which surpasses all understanding, will guard your hearts and minds through Christ Jesus. [8] Finally, brethren, whatever things are true, whatever things are noble, whatever things are just, whatever things are pure, whatever things are lovely, whatever things are of good report, if there is any virtue and if there is anything praiseworthy — meditate on these things.

How to have a peaceful heart & mind?

There's a difference between worldly wisdom & Godly wisdom. Worldly wisdom optimise human resources (God's creation) to manage & handle the challenge of life, but Godly wisdom is about our dependancy to God & Christ redemptive power (God's redemption. While worldly wisdom also mentions God as creator & the giver of wisdom, but the centrality is not God. 

There's a difference between "being happy" as what we want is fulfilled VS "rejoicing in the Lord" (verse 4), and there's a difference between "peace" as in no life challenges in our perception VS "the peace of God that surpasses all understanding". 

There's difference between "self-help" VS "God's help" (Christ-centre). That's why Paul didn't just say,"Rejoice", but "Rejoice in the Lord" (verse 4). Not "you" or "other person" is at hand, but "The Lord is at hand" (5). Don't try to depend on self-effort, but "let your requests be made known to God" (6). And (as a result) "the peace of God (not the "worldly peace" that the world offers), which surpasses all understanding (beyond logic) will guard your hearts & minds (your soul) through Christ Jesus".

John 14:27

Peace I leave with you, My peace I give to you; not as the world gives do I give to you. Let not your heart be troubled, neither let it be afraid.

At first I was confused upon reading what the Lord said in the verse above, if He leaved His peace with me then I won't be troubled nor afraid, right? Then I realised that He's not talking about peace as feeling, it is not like worldly peace. His peace is the truth & it is in the faith realm. Naturally we might feel fearful & troubled when we're facing some challenge, but what the Lord means is we can decide how the state of our heart is. Will we stay troubled and fearful, or we rest in His peace (shalom).

The Lord gave us an example about how powerful His peace is, during a bad stormy weather He was asleep on a boat, His disciples were afraid & woke Him up. Then -Mark 4:39  Then He arose and rebuked the wind, and said to the sea, “Peace, be still!” And the wind ceased and there was a great calm. 40 But He said to them, “Why are you so fearful? How is it that you have no faith?”

It's a beautiful lesson here, in the midst of feeling fearful as the disciples were facing big threat, the Lord taught them to have faith. It means we don't need to succumb to the fear, we need to realise the greatness of WHO is with us than the greatness of the storm.

Fearful thoughts come from the reality of "lack". Those thoughts want to make us feel sad, hopeless, discouraged, they are distracting us from enjoying our true reality in Christ (in whose Kingdom is "abundance"). The thoughts from the enemy are trying to rob our joy & thanksgiving to the Lord, their intention is to cloud and distract our true identity in Christ. 

The truth is Colossians 1:12-13 NKJV
[12] giving thanks to the Father who has qualified us to be partakers of the inheritance of the saints in the light. [13] He has delivered us from the power of darkness and conveyed us into the kingdom of the Son of His love,

Naturally the world will use your own fears to offer you some sort of solution & comfort while the Lord is after a relationship with you as He is everything you need. Your insecurity that comes from your perception of "lacking" opens up to the enemy's deception. Adam & Eve were created in God's image, but the serpent enticed Eve by creating a longing/desire in her to be like God.

Genesis 3:4-6 Then the serpent said to the woman, “You will not surely die. For God knows that in the day you eat of it your eyes will be opened, and you will be like God, knowing good and evil.” So when the woman saw that the tree was good for food, that it was pleasant to the eyes, and a tree desirable (Eve was feeling it) to make one wise, she took of its fruit and ate. She also gave to her husband with her, and he ate.

How do you think the devil is tricking you today? Do you think like what he did to Eve, he still uses God's name to trick you? No matter how brilliant, reasonable and sounding good the deception is, it's to bring you down. Only God brings you life.

The world makes you think about "how" to solve your problems while the Lord longs for you to think about the "WHO" is your Saviour. Trust not the worldly "how", trust on WHO your Saviour is.

Bring the thoughts that are already not from our true reality.

II Corinthians 10:5 NKJV
[5] casting down arguments and every high thing that exalts itself against the knowledge of God, bringing every thought into captivity to the obedience of Christ, 

Learn more about who you truly are, invest your time & energy knowing the real you as in God's words rather than clicking the bait . Don't trust yourself. 

Proverbs 3:5 Trust in the LORD with all your heart, And lean not on your own understanding;

Your agreement (whether towards your own thoughts/feeling or towards God's words) determine the quality of your walk with the Lord here on earth.

Nothing wrong with acknowledging feelings, but more importantly value God's words above your feeling. While the devil battles you with his cunning "feels real" deception in the realm of soul to make you agree with his reality (by showing you the fact & as if it's your own deepest sincere thoughts), learn to agree with your true reality in Christ which is written in His words.

It means you have to learn to screen your thoughts, feelings/mood to the lens of God's word, God's word is your true identity. Your true deliverance out of your problems is not found in learning to immerse "yourself" in the soul-ish realm (in the battlefield that the devil or your flesh is warring you ), but in God's word as truth.

Christ is indeed your identity. Study Him, observe Him, listen to Him, how He thinks, how He feels, what He's done, what He'll do. Trust Him, He loves you greater than your "self-love".