I find this curious, is the church for saints or sinners?? To teach and help the sinner to change his way no matter how long. Do the members no longer sin daily and need forgiveness but are pure??
I think we need to understand what you mean by saint or sinner.
In my view, a saint is a person who has believed on Jesus and his completed work, and been born again, receiving a new nature. Therefore, a saved person no longer has a nature which desires to sin, but rather, might sin, but their desire is do please God. The change is from a sinner to a saint. Only a saint, with the new creation, is a member of the church scripturally.
A carnal Christian might commit a willful sin. It is when a carnal Christian commits a willful sin, and when approached shows no remorse but rather defends or boasts. That is the person who needs to be put out of fellowship, in hopes they repent. They are to be treated as one who is not saved, or a sinner.
Now, how do we treat a sinner? Well, a sinner needs to hear the gospel of salvation. They are not members of the church, as they have a different spiritual makeup, with a desire for themselves and sin, rather then God. They need to hear the plan of God, why it was needed, Who accomplished it, and what Jesus did.
I hear this idea of a carnal Christian a lot. Where do you get this in the Bible Q? Curious.
The area which mainly introduces the idea of a carnal Christian is 1 Corintians 3
1 Cor 3:1 And I, brethren, could not speak unto you as unto spiritual, but as unto carnal, even as unto babes in Christ.
2 I have fed you with milk, and not with meat: for hitherto ye were not able to bear it, neither yet now are ye able.
3 For ye are yet carnal: for whereas there is among you envying, and strife, and divisions, are ye not carnal, and walk as men?
So, there is a mention of 'babes' being carnal. Usually in scripture carnality is applied to those who are not saved, but in this instance, it is applied to Christians. In this case, the carnality is demonstrated as contention and strife among brethren.
If we look elsewhere:
Gal 5:22 But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith,
23 Meekness, temperance: against such there is no law.
24 And they that are Christ's have crucified the flesh with the affections and lusts.
25 If we live in the Spirit, let us also walk in the Spirit.
The fruit of the Spirit becomes evident as Christians learn to walk in the Spirit and not after the flesh. Carnality is being occupied by the desires of the flesh, or relying on the flesh which is actually the way those without the Spirit, unsaved would live. But, a Christian can do things or live like an unsaved person.