Prayer is the believer's greatest necessity, because prayer is the Single Most Important Factor Needed for You to interact with God and He with you Personally.

When you spend time in the Presence of God Your Father, Seeking His Face and desiring Him as much as you do breath in your lungs and the blood that flows through your veins, then prayer is the most important necessity of your life.

Just as blood flows unceasingly, and breathing continues unceasingly; and even though you you are not conscious of it, yet it still is always going on. In the same way, you're not conscious of God, keeping you alive together in Union with Christ Jesus. Yes, he is giving you the very life of Christ himself, the same new life with which he quickened him from the dead. (Ephesians 2:5) He is keeping you in perfect Union and Fellowship with Himself, by Virtue of you Being in Christ Jesus, and confirming it by stamping you with the seal of the Holy Spirit. (Ephesians 1:13)

And He has raised you up together with Christ and made you sit down together with Him, giving you joint seating with Him in the heavenly sphere. (Ephesians ‭2:6‬)

Prayer is not an exercise, it is the spiritual way of life living in the spirit, interacting with God on a moment by moment basis unceasingly.

Your prayer life is ALWAYS God Initiated, for you to interact with God, switching your human ideas and Wishes for His Ideas and Wishes as He Imparts His Divine Persuasion
Acts 6:5-6, 14:22-23; Eph 6:16-18; Col 1:3-4; 2 Thes 3:1-2

IMPORTANT
The Holy Spirit's instruction through Peter was to: unceasing in prayer. 1 Thessalonians 5:17 This simply means, to turn your thoughts to God, depending on the Holy Spirit in you to stir you continuously, to interact with God on a moment by moment basis throughout the day, to know what God prefers in each moment of your day. So, it you are able to maintain an interrupted and constant spirit of prayer, by the Holy Spirit Himself Testifying with your own spirit, assuring you what God prefers and all the affairs of life. Romans 8:16

Remember, God is always with you. When you were born again of the Spirit of God, God came and made his home with in you. Your body is now the Temple of the living God, the Holy Spirit of God lives in you. Your life is hidden with Christ in God, Christ lives in you. Your body is wholly Filled and flooded with the Godhead – God the Father, God the Son, God the Holy Spirit. (Colossians 2:10)

So, Prayer without Ceasing Is a Practical Experience in the Life of the Believer, Because There Are No Gaps in Time or Intervals That God Is Not with You. He Is Instantly Available to You at Any Moment. Simply look away from all distractions you, and interact with God by Simply listening to what God tells you, and asking God what you should do throughout the day in all things.

An important point is Jesus never mentioned unanswered prayer, He Had the Boundless Certainty That Prayer Is Always Answered.

This Certainty Comes from knowing that all your prayers are answered in Christ Jesus. What did Jesus say?

Ask, and it will be given to you; seek, and you will find; knock, and it will be opened to you. For everyone who asks receives, and he who seeks finds, and to him who knocks it will be opened.”
‭‭Matthew‬ ‭7:7-8‬ ‬

And whatever you ask in My name, that I will do, that the Father may be glorified in the Son. If you ask anything in My name, I will do it. (The Greek word literally means he will calls it to happen.) ‭‭John‬ ‭14:13-14‬ ‬

God answers prayer in the best way, not sometimes, but every time, although the immediate manifestation of the answer in the neck from may not be what we expect. The difficulty is man uses his human reasoning to help God determine how to feel his prayers. God answers all prayers!

However when you don't see him manifest the prayer as you thought then you're looking at it from your perspective and not his perspective. You expect Wrongly not knowing,

God being a partner in your prayers, the Holy Spirt comes to your aid and bears you up in your weakness; for you do not know what prayer to offer nor how to offer it worthily as we ought, but the Spirit Himself goes to meet your supplication and pleads in your behalf with unspeakable yearnings and groanings too deep for utterance.

And God Who searches the hearts of men knows what is in the mind of the Holy Spirit, what His intent is, because the Spirit intercedes and pleads before God in behalf of the saints according to and in harmony with God's will. (Ps. 139:1, 2)

So, you are assured and know that God being a partner in your prayers in all things work together and are fitting into a plan for good to and for those who love God and are called according to His design and purpose, for you who are in Christ Jesus. Romans‬ ‭8:26-28‬ ‬

God knows what you need even before you ask him, He's the one that draws you to himself to interact with Him. And He Living within you Understands All your Thoughts, Feeling and Purposes. Matthew 6:8, 1 Corinthians 6:19, Galatians 2:20, Hebrews 4:13