Despite their fool differences between them, the Apostle Paul had desribed them in the following manner...
1 Corinthians 1:2 Unto the church of God which is at Corinth, to them that are sanctified in Christ Jesus, called to be saints, with all that in every place call upon the name of Jesus Christ our Lord, both theirs and ours: 1:3 Grace be unto you, and peace, from God our Father, and from the Lord Jesus Christ. 1:4 I thank my God always on your behalf, for the grace of God which is given you by Jesus Christ; 1:5 That in every thing ye are enriched by him, in all utterance, and in all knowledge; 1:6 Even as the testimony of Christ was confirmed in you: 1:7 So that ye come behind in no gift; waiting for the coming of our Lord Jesus Christ: 1:8 Who shall also confirm you unto the end, that ye may be blameless in the day of our Lord Jesus Christ. 1:9 God is faithful, by whom ye were called unto the fellowship of his Son Jesus Christ our Lord.
True, he had had to lament what is often obviously also the case on the part of some within so called MAD against anyone who does not hold their views.
1 Corinthians 1:10 Now I beseech you, brethren, by the name of our Lord Jesus Christ, that ye all speak the same thing, and that there be no divisions among you; but that ye be perfectly joined together in the same mind and in the same judgment. 1:11 For it hath been declared unto me of you, my brethren, by them which are of the house of Chloe, that there are contentions among you.
1 Corinthians 3:1 And I, brethren, could not speak unto you as unto spiritual, but as unto carnal, even as unto babes in Christ. 3:2 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. 3:3 For ye are yet carnal: for whereas there is among you envying, and strife, and divisions, are ye not carnal, and walk as men?
Again, that is in contrast to what he had also said of them as he began his letter to them.
And that kind of thing is exactly what you have run into, in the likes of a DP and some others out there.
It is crystal clear obvious from those three chapters, and more, that the Corinthians were not on the same page about the Apostle Paul either...
1 Corinthians 1:10 Now I beseech you, brethren, by the name of our Lord Jesus Christ, that ye all speak the same thing, and that there be no divisions among you; but that ye be perfectly joined together in the same mind and in the same judgment. 1:11 For it hath been declared unto me of you, my brethren, by them which are of the house of Chloe, that there are contentions among you. 1:12 Now this I say, that every one of you saith, I am of Paul; and I of Apollos; and I of Cephas; and I of Christ.
1 Corinthians 3:3 For ye are yet carnal: for whereas there is among you envying, and strife, and divisions, are ye not carnal, and walk as men? 3:4 For while one saith, I am of Paul; and another, I am of Apollos; are ye not carnal? 3:5 Who then is Paul, and who is Apollos, but ministers by whom ye believed, even as the Lord gave to every man?
Again, there is ever more to learn AFTER one is saved...
But THAT is a separate; a DIFFERENT issue.
Some things differ.
Some only appear to.
Some things are the same.
Some only appear to be.
Your best option when dealing with such is to rest in your having been accepted into God's family if you have believed the above passages from Romans 3 and Romans 5.
That, and the following...
It is what I did when I first believed the above.
The result being that I came to hold to the beginnings of my present understanding, way before I'd ever heard of the so called MAD of one group or another (for there are different groups, with different key understandings, as with any other school of thought within Christianity).
Keep the following in mind when dealing with such, and you'll be just fine.
Galatians 6:12 As many as desire to make a fair shew in the flesh, they constrain you to be circumcised; only lest they should suffer persecution for the cross of Christ. 6:13 For neither they themselves who are circumcised keep the law; but desire to have you circumcised, that they may glory in your flesh. 6:14 But God forbid that I should glory, save in the cross of our Lord Jesus Christ, by whom the world is crucified unto me, and I unto the world. 6:15 For in Christ Jesus neither circumcision availeth any thing, nor uncircumcision, but a new creature. 6:16 And as many as walk according to this rule, peace be on them, and mercy, and upon the Israel of God.
Romans 16:24 The grace of our Lord Jesus Christ be with you all. Amen. 16:25 Now to him that is of power to stablish you according to my gospel, and the preaching of Jesus Christ, according to the revelation of the mystery, which was kept secret since the world began, 16:26 But now is made manifest, and by the scriptures of the prophets, according to the commandment of the everlasting God, made known to all nations for the obedience of faith: 16:27 To God only wise, be glory through Jesus Christ for ever. Amen.