These requirements (or sacraments) include hearing, believing, repenting from sin, confessing the name of Christ, and being baptized in water, and then once in a saved condition, that we keep ourselves saved by being faithful and continuing to live a moral and religious good life.
In Church of Christ language this is sometimes called 'following the gospel', 'meeting God's conditions of pardon', 'following the New Testament Pattern' or 'the 5 step plan of salvation' and is a gospel theology teaching salvation by New Testament Law-Keeping.
Now humanly speaking, it is certainly an understandable assumption.
However biblically speaking, there are a number of problems with this view.
First and foremost is that sacramentalism, or 'obedience to the necessary moral and religious requirements of the New Testament', is not how a person responds the gospel of Jesus Christ.
Rather, The Gospel or The Good News Message is that Jesus came, died on the cross, paid the full penalty for our sin, that He was buried, and that on the Third Day God raised Him from the dead. 1 Cor. 15:1-4
How we are to respond to the gospel message is to believe.
That is, we are to believe God's promise, trusting in Jesus Christ and Him alone to save us. 1 Cor. 15:11
The second problem with the Church of Christ view of the gospel is that, as illustrated with the Pelagian Controversy, it does not take into account the dynamics of the fall of man.
The Bible tells us that because of Adam's sin, man is a sinner both by nature and by choice, and that even as believers we all sin and continue to stumble in many ways. Since God is holy, perfect, and just and will not allow sin into heaven, He cannot accept anything less than perfect obedience.
And because man is ever sinful and has a predisposition to sin and to do evil, never always able to do the right thing, the right way, for the right reason, we simply do not have the ability to save ourselves through our own moral or religious obedience, or in other words- New Testament law keeping.
As shown in Romans 3:9-20, the status of fallen man is that he has never been a law-keeper, but rather that HE IS A LAW-BREAKER.
Thus, sinful man is in desperate need of a Savior since he is unable to save himself.
So what is the solution?
In Romans 9:30-31 Paul makes a interesting contrast between those 'trying to be made righteous by what they do' (i.e. sacramentalism) with those 'who are trusting in Christ who alone makes people righteous' (salvation by grace through faith).
He writes,
"What then shall we say? That the Gentiles, who did not pursue righteousness, have obtained it, a righteousness that is by faith; but the people of Israel, who pursued the law as the way of righteousness, have not attained their goal."
Why not?
"Because they pursued it not by faith but as if it were by works of the law.”
Continuing in the context, Paul tells us that the people of Israel missed the gospel because-
"Christ is the end of the law for righteousness to everyone who believes." Romans 10:4
Summary
To those in the Church of Christ, the '5 step plan of salvation' is a moral and religious process we must do and accomplish in order to be saved. Evangelical Christianity believes that we are saved by trusting in the One who can save, that is, salvation though faith in Jesus Christ.
Members of the Church of Christ correctly understand that a belief the facts alone can not save. Unfortunately many fail to understand that there is a radical difference between believing the facts of John 3:16 and believing in the promise of John 3:16.
Thus, they have drawn the conclusion that the righteousness we need must then come to us through our own imperfect obedience to 'the necessary' requirements of the New Testament, rather than coming to understand that God has provided the very righteousness we need literally through faith in the person of Jesus Christ.
Now for those in the Church of Christ who believe we are saved by our obedience to all of the necessary moral and religious commands of the New Testament, that in heaven- I’ll be the first to come up and shake your hand. By reaching heaven through "New Testament Law-Keeping", you will have certainly accomplished an incredible and monumental task!
But there are those who are trying to share the good news about the gift of perfect righteousness that God provides as a gift to all, and upon all, who place faith in Jesus Christ, which is far superior to anything we can ever hope to attain through our own imperfect obedience.
It is the very righteousness of Jesus Christ Himself, given to all those who will place faith and trust in Him, because JESUS has become for us OUR RIGHTEOUSNESS, HOLINESS, AND REDEMPTION. 1 Cor. 1:30
References to consider:
Romans 3:21-31, 4:1-25, 5:1-2, 10:4, 9-10, 11:17-20
Galatians 2:16-17, 3:1-23
Ephesians 2:8-10
Philippians 3:1-9