God's words warn us that if any person or angel comes to us telling us another gospel, other than the words that we have been given, we are to understand that the prophets are not of God, but false prophets, and the angels are fallen angels, not Godly angels. God changes His Truth for no one. He will keep His words. The Bible did not come of one man's private interpretation (not Muhammad, Joseph Smith, Charles Taze Russell) but the gospel has been preserved, and the words of many prophets over a span of many years. Joseph Smith, Muhammad, Charles Taze Russell ... these men did not rediscover the lost truth, that was never lost to begin with. The cults do not take God's words at face value, but take His words out of their rightful context in the Scriptures, and insert His words into a different context, the doctrines of their own making, thus changing the interpretation, redirecting man from God's truth onto lies and deception.
The book of Revelation pronounces a curse on those who add or take away from God's words, and this is not the only book of the Bible which does this. Jehovah's Witnesses take what they want out of the Bible that they want to believe is true, and reject whatever they do not wish to agree with, namely the deity of Jesus, explanation that He is not an angel...etc... When people heed God's words, they stay on the right path, as God's words are a lamp unto our feet and a light unto our path, and that is the path to life. To depart from God's words is rebellion against His authority. One cannot be a follower unless he/she is a follower of their Teacher's teachings. Those who depart, depart. Those who follow, follow.
Cults always find a way around God's words. Jesus said to beware of the leaven of the Pharisees, and the Bible explains to us what this is... these are those who placed their own teachings and doctrines above the Scriptures, and even made themselves out to be special mediators between the people and God... which is a doctrine of the Nicolaitanes (which means the conquering of the laity/people), which Jesus said He hated twice, in the book of Revelation. People repeat the same error of Adam and Eve in the garden of Eden, when they turn aside to cults. When presented with God's truth and then the contradicting words of Satan which cast doubt on God's words, Adam and Eve chose the way that accursed them by placing their trust in satan, and to whom one has allowed themselves to be overcome by, the same is the servant of.
They exchanged God as their authority figure to the devil... and dominion transferred from God to Satan, and this is why Jesus (the God who made this world) said that His kingdom is not of this world. He is not saying that He did not make the world, but that He is not operating as King of this world -- not yet anyway. The Bible protects us from errors, and the Scriptures are our safeguard and guard rails. But they only protect us if we read them and believe in them. God knows every person who trusts in Him, and we are not believers in Him if we are not believers in His words.
“Then he said unto them, O fools, and slow of heart to believe all that the prophets have spoken:” - Luke 24:25, KJV
“Jesus answered and said unto them, Ye do err, not knowing the scriptures, nor the power of God.” - Matthew 22:29, KJV
“Whosoever transgresseth, and abideth not in the doctrine of Christ, hath not God. He that abideth in the doctrine of Christ, he hath both the Father and the Son.” - 2 John 1:9, KJV
He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him. - 1 John 2:4, KJV
And why call ye me, Lord, Lord, and do not the things which I say? - Luke 6:46, KJV
John 8:43-47, KJV
43, Why do ye not understand my speech? even because ye cannot hear my word.44, Ye are of your father the devil, and the lusts of your father ye will do. He was a murderer from the beginning, and abode not in the truth, because there is no truth in him. When he speaketh a lie, he speaketh of his own:1 for he is a liar, and the father of it.45, And because I tell you the truth, ye believe me not.46, Which of you convinceth me of sin? And if I say the truth, why do ye not believe me?47, He that is of God heareth God's words: ye therefore hear them not, because ye are not of God.
“But whoso keepeth his word, in him verily is the love of God perfected: hereby know we that we are in him.” - 1 John 2:5, KJV
“He that hath my commandments, and keepeth them, he it is that loveth me: and he that loveth me shall be loved of my Father, and I will love him, and will manifest myself to him.” - John 14:21, KJV
“He that rejecteth me, and receiveth not my words, hath one that judgeth him: the word that I have spoken, the same shall judge him in the last day.” - John 12:48, KJV
26 For whosoever shall be ashamed of me and of my words, of him shall the Son of man be ashamed, when he shall come in his own glory, and in his Father's, and of the holy angels. - Luke 9:26, KJV
1. My son, keep my words, and lay up my commandments with thee. 2 Keep my commandments, and live; and my law as the apple of thine eye. 3 Bind them upon thy fingers, write them upon the table of thine heart. - Proverbs 7:1-3, KJV
20 My son, attend to my words; incline thine ear unto my sayings. 21 Let them not depart from thine eyes; keep them in the midst of thine heart. 22 For they are life unto those that find them, and health to all their flesh. - Proverbs 4:20-22, KJV
“It is the spirit that quickeneth; the flesh profiteth nothing: the words that I speak unto you, they are spirit, and they are life.” - John 6:63, KJV
Add thou not unto his words, lest he reprove thee, and thou be found a liar. - Proverbs 30:6, KJV
“Thus saith the LORD; Stand in the court of the LORD'S house, and speak unto all the cities of Judah, which come to worship in the LORD'S house, all the words that I command thee to speak unto them; diminish not a word:” - Jeremiah 26:2, KJV
2 Ye shall not add unto the word which I command you, neither shall ye diminish ought from it, that ye may keep the commandments of the Lord your God which I command you. - Deuteronomy 4:2, KJV
Thy word is true from the beginning: and every one of thy righteous judgments endureth for ever. - Psalm 119:160, KJV
6 The words of the Lord are pure words: as silver tried in a furnace of earth, purified seven times. 7 Thou shalt keep them, O Lord, thou shalt preserve them from this generation for ever. - Psalm 12:6-7, KJV
8 But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed. 9 As we said before, so say I now again, if any man preach any other gospel unto you than that ye have received, let him be accursed. - Galatians 1:8-9, KJV
https://www.bible.com/bible/1/REV.22.18-20.KJV
http://www.kjvtoday.com/home/does-the-second-them-in-psalm-127-refer-to-gods-words
To worship God is to put Him first. His words above all, His authority above all, trust in Him above all. Loyalty is owed to Him, not to them. God gave us His Truth and the believers in Him, believe Him.