One of the reasons why Reformed Theology gets a slap in the face by "Easy Christianity's" theology is because they adhere to a superficial belief. The quote above by Dr. John F. MacArthur stresses the fact that true, believing is essential but there's more than just superficial belief. James warns in James 2:19 warns that the devils believe and tremble. The demons believe Jesus is the Son of God but it's a superficial belief. That is the huge warning about superficial faith. Many people today say that the idea of salvation is by faith alone but not by a faith alone is contradictory. As James also stresses in James 2:14, "Can faith save him?" which can be restated as, "Can that faith save him?" If one has real genuine belief in Jesus Christ, there ought to be a change in one's lifestyle and attitude towards sin as they mature in their Christian lives. Even the most immature of Christians cannot live like devils because they are saved.
When Jesus says it, He means it and you got to believe it. Reading through Matthew, Mark, Luke and John makes me see that Jesus means business. When Jesus said that whoever rejects Him rejects the Father, He means it (Luke 10:16). When He said that He's the only Way to Heaven and no other, He means it (John 14:6). When He stresses the needed that you are a dirty sinner and you need to be forgiven, you need to humble yourself, He means it. While I could go ahead and sort out the teachings of Christian preachers and disagree at some point, I cannot disagree with Jesus because what He says, He means business because He is the Son of God, He is the Second Person of the Trinity and He is the Word, the Word was with God and the Word is God (John 1:1-13). Since He is God, what He says, He means it. His perfect harmony with His Father and the Holy Spirit, the Trinity is three in Person and one in essence (God) and they are One. They cannot disagree with each other because they are in perfect harmony. To deny the Godhead is to teach another Jesus which many heretics later like Arius and Pelagius had planted these seeds which still persist today.
One reason why it's very hard to get saved even if salvation is not by works is because of the pride of life and Jesus calls people to humble themselves. Humility is not an easy trait to practice because fallen man is proud and arrogant. The notion that if you are good enough you will enter Heaven is more popular than what James 2:10-11 says the truth that if you just break one of God's rules, you have violated the perfect precept of the Law which goes against that if I keep most of the commandments, I am safe and secure. Ephesians 2:8-9 says that salvation is by grace through faith and not of works so nobody can brag that they got saved by their own achievement. The religion centered on human achievement is hypocritical. Many people can say, "Well I am a good person." but the lifestyle gives away the fact that they are fallen sinners. It is very common to meet somebody devoted to false religion and ritualism while they are vile sinners at the same time. People tend to think that God will reward them for their works only to find out that their secrets sins were exposed on judgment day when they are told the awful truth they were never saved to start with (Matthew 7:21-23). If a person is too filled with pride, they will never accept the free gift of salvation.
Refusal to submit to His Lordship is where a lot of people fall when they refuse the Lord Jesus Christ. Many people realize that if they get saved, then it's time for a new start. Whenever a person refuses to receive the Lord Jesus Christ, there's the tendency that the person will admit that they love committing certain sins while they tend to contradict themselves by saying nothing is wrong with them. Jesus is Lord and there's no question about that and every person who gets saved Has Him as Lord as a result of one's salvation. When a person gets saved, they have begun their first step in submission to the Lordship of Christ. When one is truly saved, that submission to Jesus' Lordship continues from acknowledgement to good works. Many people today just want Jesus as Savior but not as their Lord. I don't see how that's possible in the Light of the Word of God because it's utter heresy. Once they see that Christianity means going to a new life, it's a makeover, that Jesus is not an addition then they refuse the true Gospel. They will accept any "gospel" that caters to their sinful wants rather than their spiritual need to get right with God through Jesus Christ.
If your Jesus is not Lord, you were never saved to start with because you trust in another Jesus. He is not Savior, He is also Lord and many people today are not willing to let Jesus be their Lord. If works salvation is not the only problem we also have "Easy Christianity" that teaches one can receive Jesus as Savior then make submission to Him as Lord completely optional. If you are saved, submission is not optional but inevitable because before you got saved, didn't you know Jesus as Lord of Lords? The fact that the offended Lord Jesus still died for you in spite of your unworthiness, does not make the person say, "Lord I am your slave, how can I serve you?" because He is the Lord of every Christian? As the Savior of Christians, the Christians are His servants because He is Lord. People who love their sin hate the light because their deeds will be reproved but those who are His come into the light because they are saved (John 3:20-21) because you cannot love sin and the Savior. When a person is a Christian, when they are saved they are saved from sin, not in their sins.