Here are three very important MUSTS that are in the Bible.

The Greek dictionary/lexicon meanings: for the word MUST using Strongs numbers.
*NT: 1163
dei (die); third person singular active present of NT: 1210; also deon (deh-on'); neuter active participle of the same; both used impersonally; it is (was, etc.) necessary (as binding):

*KJV-behoved, be meet, MUST (needs), (be) need (-ful), ought, should.

NT: 1210
deo (deh'-o); a primary verb; to bind (in various applications, literally or figuratively):

KJV-bind, be in bonds, knit, tie, wind.

Webster’s dictionary defines MUST (1) used to express compulsion obligation, requirement, or necessity. (2) to express probability. (3) used to express certainty or inevitability.

The first important MUST is found in the following scriptures and is stated by Jesus.

John 3:1-8
1 Now there was a man of the Pharisees, named Nicodemus, a ruler of the Jews;
2 this man came to Jesus by night and said to Him, "Rabbi, we know that You have come from God as a teacher; for no one can do these signs that You do unless God is with him."
3 Jesus answered and said to him, "Truly, truly, I say to you, unless one is born again he cannot see the kingdom of God."
4 Nicodemus said to Him, "How can a man be born when he is old? He cannot enter a second time into his mother's womb and be born, can he?"
5 Jesus answered, "Truly, truly, I say to you, unless one is born 'of' water and the Spirit he cannot enter into the kingdom of God.
6 "That which is born 'of' the flesh is flesh, and that which is born 'of' the Spirit is spirit
7 "Do not be amazed that I said to you, "You MUST (NT: 1163 dei) be born again.'
8 "The wind blows where it wishes and you hear the sound of it, but do not know where it comes from and where it is going; so is everyone who is born 'of' the Spirit.” (*NASBU)

One key word here is "of", that which you are born "of" is what you become, water and Spirit. The water is a symbol for the word of God and the spirit is a symbol in this case for life or living. You become living water or a life of the word.

The second important MUST is found in the following scriptures and again is stated by Jesus.

John 4:20-24
20 "Our fathers worshiped in this mountain, and you people say that in Jerusalem is the place where men ought to worship."
21 Jesus said to her, "Woman, believe Me, an hour is coming when neither in this mountain nor in Jerusalem will you worship the Father.
22 "You worship what you do not know; we worship what we know, for salvation is from the Jews.
23 "But an hour is coming, and now is, when the true worshipers will worship the Father in spirit and truth; for such people the Father seeks to be His worshipers.
24 "God is spirit, and those who worship Him MUST (NT: 1163, dei) worship in spirit and truth.” (NASBU)

Worship connects our affection, desire and love to the Father, and is a personal, living relationship. This relationship is a life in, of and from the Word of God, or in spirit and truth; the word “spirit” in many cases from the Hebrew and Greek contains the meaning “life”. Hence, God is life and we must act with Him in life and truth.
(See John 15:1-10)

The Apostle Paul writes the third important MUST in the scriptures to the Hebrews.

Heb 11:1-3 and 6
1 Now faith is the substance of things hoped for, the evidence of things not seen.
2 For by it the elders obtained a good testimony.
3 By faith we understand that the worlds were framed by the word of God, so that the things which are seen were not made of things which are visible.
6 But without faith it is impossible to please Him, for he who comes to God MUST believe that HE IS, and that He is a rewarder of those who diligently seek Him. (*NKJV)

These scriptures from Paul to the Romans can help us to see how to determine our belief.
Rom 10:10-11 for with the heart man believes, resulting in righteousness, and with the mouth, he confesses, resulting in salvation. For the Scripture says, "Whoever believes in Him will not be disappointed.” (*NASB)

Our belief comes from our affections, desires or love (heart, our will). Our mouth confesses it or we act upon it. Jesus said that out of our innermost being will flow “rivers of living water”. If one does not believe that HE IS, they will not act on it from a true heart. A hypocrite can act upon what they do not believe, because they do not have any affection, desire or love (the true heart) for what is good and true (what HE IS), but only love for themselves and the things of the world. (e.g. Ask anyone if he or she should quit smoking) These spurious loves will take the Bible and use scriptures to support the end of the love of self and love of the world. When one does believe that HE IS, self takes a back seat and our heart is changed. His will, affections and desires become ours and we begin to love God and one another. We are set free from the power and effects of sin, i.e. salvation.

“Within the printed Word is a ‘wellspring of life’ to those who hunger and thirst after His righteousness, whose source is the Spirit of God. To those who do not seek His righteousness within the printed Word, it is a ‘well of opinion’ from which they are the source”. ©rdlb 2004

Here are some more relevant scriptures that might be interesting to review.

Isa 28:16 Therefore thus says the Lord GOD,
"Behold, I am laying in Zion a stone, a tested stone,
A costly cornerstone for the foundation firmly placed.
He who believes in it will not be disturbed, (i.e. disappointed, NASBU).

Jer 31:33-34 "But this is the covenant which I will make with the house of Israel after those days," declares the LORD, "I will put My law within them and on their heart I will write it; and I will be their God, and they shall be My people. "They will not teach again, each man his neighbor and each man his brother, saying, "Know the LORD,' for they will all know Me, from the least of them to the greatest of them," declares the LORD, "for I will forgive their iniquity, and their sin I will remember no more." . (NASBU)

Six times, in these two verses, "I will" is used; (six is the number for man, for on the sixth day man was created), this is something God wants to personally, (I will) do in His New Covenant. Remember John 3:16, "For God so loved the world that He gave His only begotten Son that, whomsoever believes on Him shall have eternal life".

Heb 8:10-13 For this is the covenant that I will make with the house of Israel after those days, saith the Lord; I will put my laws into their mind, and write them in their hearts: and I will be to them a God, and they shall be to me a people: And they shall not teach every man his neighbour, and every man his brother, saying, Know the Lord: for all shall know me, from the least to the greatest. For I will be merciful to their unrighteousness, and their sins and their iniquities will I remember no more. In that he saith, A new covenant, he hath made the first old. Now that which decayeth and waxeth old is ready to vanish away. (KJV)

Here the Apostle Paul uses "I will" five times in his quote from the OT; five is the number for grace and mercy.

In my study of churches and their doctrines and making comparisons between them and the scriptures, I find it interesting that conclusions drawn from the letter (literal print) of the Bible does create a wide variety of opinion about the “MUST” born “of” the water and of the spirit. Some believe in baptizing (birthing) with water as infants, some when a child reaches twelve or thirteen, after one becomes “saved” and many other thoughts and ideas that lift up the material ritual and miss the point. The methods vary from sprinkling water on the forehead, emersion in a tank of water in a church building, to any river or lake, to only at the river Jordan in Israel. Yet all of these ways to perform a ritual cannot provide a true “born of” water and of spirit experience. Point, an individual does not become a sprinkling, a tank, lake or even the river Jordan. Point, when an individual immerses oneself into the Bible, (baptized into Christ and has put on Christ) they are allowing the Spirit to manifest or reveal itself to them. Then the individual begins to take on the characteristics of the living Word of God, a true birthing takes place. This “birth” creates the beginning to know the Father even as the Father knows us. (John 17:21-25) We must be born again, we must worship God in Spirit and in Truth, and we must believe that He Is and that He Is a rewarder to them that diligently seek Him.

*NT (New Testament), KJV (King James Version), NJKV (New King James Version), NASB (New American Standard Bible), NASBU (New American Standard Bible Updated)

Jas 2:14-26
4 Faith and Works
What use is it, my brethren, if someone says he has faith but he has no works? Can that faith save him? 15 If a brother or sister is without clothing and in need of daily food, 16 and one of you says to them, " Go in peace, be warmed and be filled," and yet you do not give them what is necessary for their body, what use is that? 17 Even so faith, if it has no works, is dead, being by itself. 18 But someone may well say, "You have faith and I have works; show me your faith without the works, and I will show you my faith by my works." 19 You believe that God is one. You do well; the demons also believe, and shudder. 20 But are you willing to recognize, you foolish fellow, that faith without works is useless? 21 Was not Abraham our father justified by works when he offered up Isaac his son on the altar? 22 You see that faith was working with his works, and as a result of the works, faith was perfected; 23 and the Scripture was fulfilled which says, "AND ABRAHAM BELIEVED GOD, AND IT WAS RECKONED TO HIM AS RIGHTEOUSNESS," and he was called the friend of God. 24 You see that a man is justified by works and not by faith alone. 25 In the same way, was not Rahab the harlot also justified by works when she received the messengers and sent them out by another way? 26 For just as the body without the spirit is dead, so also faith without works is dead. NASU

When one is living the life in and from the heart, there is no need of a defense. When one has to continually defend a "church" because of impropieties from one or more individuals or groups within, where is the true "Faith"? One begins to defend sand and tries to shore up the very "sands of impropiety" and thereby rebuilding the very thing that needs to be destoyed.

2 Co 6:16-18
For we are the temple of the living God. As God has said: "I will live with them and walk among them, and I will be their God, and they will be my people."
17 "Therefore come out from them
and be separate,
says the Lord.
Touch no unclean thing,
and I will receive you."
18 "I will be a Father to you,
and you will be my sons and daughters, (NIV)

It is hard to separate from those who play in thier sand boxes and join those who cling to the "Rock". Three decades ago I had one of the first of many dreams (still have them now), very real and pointed.
In this dream I was walking with many "christians" along a dirt road in a valley with the full sun shine on us, between two long ridges full of dry grass. I wanted to see where everyone was going to and climbed to the top of the ridge to my right. When I got to the top and looked to where the crowd was going I was supprised to realize it was towards the edge of a precipice with a deep canyon of darkness. No one seemed to stop at the edge, they just walked off it. I understood that this was not the way to go and turned and looked from the top of this ridge to look in the opposite direction and saw a lush green valley. A river was flowing through it and along the edge of this river were trees and other green plants. I found myself drawn to the other side of the river and to what I came to realize was my house. The outside of this house was all neat, freshly painted and proper. When I went inside I discovered my wife trying to make up our bed. As I wandered around the inside of my house, I also realized how dusty, dirty and full of cobwebs all of the furniture and belongings were.

It is still interesting to me the reality that that dream gave to me today. I can still vividly recall even the smells from the dry grass, the green valley, the river and even the dust in my house. I have found how many lend themselves to extroversion and introversion, rather than to introspection on matters of "Faith". The principal of the "beam and mote" come readily to mind, those individuals that you have reminded us of must have removed much of their "beam" and thereby allowed their lives to remove the "mote" from the eyes of others. I will continue to clean my house as the Lord points out those "spots of flesh", those grains of sand from my sand box playing days.