If one truly believes in God and puts Him first, He will bring that one to maturity the quickest. If the believer doesn't put God first (still many have to learn this), the growth will be negligible; but yet saved.
Well, the problem becomes when they change Gods Word so you cannot tell what it says. take a look at these verses which clearly say one thing, then are changed by these new versions which distort and give another meaning.
1 John 2:3
And hereby we do know that we know him, if we
keep his commandments.
NIV
Whoever says, “I know him,” but does not do what he commands is a liar, and the truth is not in that person.
1 John 2:4
He that saith, I know him, and
keepeth
not his commandments, is a liar, and the truth is not in him.
NIV
Whoever says, “I know him,” but does not do what he commands is a liar, and the truth is not in that person.
1 John 3:22
And whatsoever we ask, we receive of him, because we
keep his commandments, and do those things that are pleasing in his sight.
NIV
and receive from him anything we ask, because we keep his commands and do what pleases him.
1 John 3:24
And he that
keepeth his commandments dwelleth in him, and he in him. And hereby we know that he abideth in us, by the Spirit which he hath given us.
1 John 5:2
By this we know that we love the children of God, when we love God, and
keep his commandments.
NIV
This is how we know that we love the children of God: by loving God and carrying out his commands.
1 John 5:3
For this is the love of God, that we
keep his commandments: and his commandments are not grievous.
NIV
In fact, this is love for God: to keep his commands. And his commands are not burdensome,
Revelation 12:17
And the dragon was wroth with the woman, and went to make war with the remnant of her seed, which
keep the commandments of God, and have the testimony of Jesus Christ.
NIV
Then the dragon was enraged at the woman and went off to wage war against the rest of her offspring—those who keep God’s commands and hold fast their testimony about Jesus.
Revelation 14:12
Here is the patience of the saints: here are they that
keep the commandments of God, and the faith of Jesus.
NIV
This calls for patient endurance on the part of the people of God who keep his commands and remain faithful to Jesus.