Why was the Apostle Paul seemingly not that interested in baptizing believers?

Why ==> He didn't put it that way. Baptism is important.

Paul just said that He is GLAD for not baptizing the Corinthians (in question). Other wise they would follow him instead of Christ Jesus. Those Corinthians (in question) were notorious for following idols.

This is also how denominations think: If I get baptize in the Catholic church then I am a Catholic. BUT, According to the scripture in question, If I really get baptize in the name of Christ INSIDE a Catholic chruch, then no only should I be a Catholic, BUT also a Mormon, Jehova Witness, Mormon, a Pentocastal, etc, since they also baptize in the name of Christ.

Or the OPPOSITE would be that am only a Catholic because I was baptize in the name of the Pope.

In anyway, the scripture in question is a rebuke to the Corinthians (in question). Not us right.

thanks for reading

In answering this question, I first want to requote the passage quoted above in the second answer
(1 Cor 1.10-14,16-18), but this time including the omitted verse (v 15), which interestingly enough is the verse which answers the question) and omitting the final verse (v 18). Reading the whole passage (vv.10-17) is useful because it provides the context for the single line of Paul's letter which is quoted in the question (v 17). I use the KJV:

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. 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. 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. 13 Is Christ divided? was Paul crucified for you? or were ye baptized in the name of Paul? 14 I thank God that I baptized none of you, but Crispus and Gaius; 15 Lest any should say that I had baptized in mine own name. 16 And I baptized also the household of Stephanas: besides, I know not whether I baptized any other.
17 For Christ sent me not to baptize, but to preach the gospel: not with wisdom of words, lest the cross of Christ should be made of none effect.

Notice that Paul acually gives us the reason that Ha-Masciach (Christ) sent him not to baptise in verse 15: 'Lest any should say that I had baptized in mine own name.' The point Paul is making here is on the subject of names (which is instructive when considering the subject of denominations, since the word denomination means to give something a name). Believers are not given the Holy Spirit to glorify any name except the name of Yahshua. The point is that believers are to be united in glorifying this noble name in word and in deed, rather than divided. Thus it is wrong to say "I'm of Apollos" or "I'm of Cephas" or "I'm pentecostal" or "I'm baptist" or "I'm Church of England" or even "I'm of Christ". He's not saying it's wrong to say "I'm of Christ" in general: only when it's in the context of dividing yourself from other believers who are saying they're of some other name. The point is clear: unity is essential. It's so essential that there are cases where you shouldn't even say you are of Christ because you'll wound and alienate others (who are your brothers and sisters in The Lord) who are saying they are of some person or name other than Christ.

He also is not saying that baptism is unnecessary (or else why would he have baptised anyone). Neither is he nullifying these word of Yahshua:

16 He that believeth and is baptized shall be saved; but he that believeth not shall be damned. (Mark 16.16).

What he's saying is that noone should baptise in their own name, or even be seen to be doing so, because in doing so there is a danger that people will begin to divide on the basis of favouring one person who is baptising over another, when in fact we need to recognise that we are to be united in glorfying The Lord: we are called to be colabourers, as he says in these passages:

13 For not even those who are circumcised keep the law, but they desire to have you circumcised that they may boast in your flesh. 14 But God forbid that I should boast except in the cross of our Lord Jesus Christ, by whom the world has been crucified to me, and I to the world.
(Galatians 6.13-14)

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? 4 For while one saith, I am of Paul; and another, I am of Apollos; are ye not carnal? 5 Who then is Paul, and who is Apollos, but ministers by whom ye believed, even as the Lord gave to every man? 6 I have planted, Apollos watered; but God gave the increase. 7 So then neither is he that planteth any thing, neither he that watereth; but God that giveth the increase. 8 Now he that planteth and he that watereth are one: and every man shall receive his own reward according to his own labour. 9 For we are labourers together with God: ye are God's husbandry, ye are God's building. 10 According to the grace of God which is given unto me, as a wise masterbuilder, I have laid the foundation, and another buildeth thereon. But let every man take heed how he buildeth thereupon. 11 For other foundation can no man lay than that is laid, which is Jesus Christ.
(1 Cor 3.1-11)

Since Yahshua Ha-Maschiach (Jesus Christ) is the foundation and no man can lay any other, we ought to be careful to avoid nullifying or doubting His words, which I quote again:

16 He that believeth and is baptized shall be saved; but he that believeth not shall be damned. (Mark 16.16).

The apostle Peter warned us to be very careful when reading Paul's letters in 2 Peter 3.15-16:

15 And account that the longsuffering of our Lord is salvation; even as our beloved brother Paul also according to the wisdom given unto him hath written unto you; 16 As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction.

In response to your comment Mike, I don't believe Paul thought baptism was unimportant, since he did baptise people. Why would a man as serious and dedicated as Paul waste his time doing anything he thought unimportant?

I do think it may be worth stating my final argument though, as you suggest. My final argument is not that Paul put unity above baptism, but rather that he put unity above his needing to be the one to baptise every single new believer he could: it was ok for someone else to do the baptising. That Paul recognised the crucial importance of baptism is evident from the following excerpts from his letters:

3 Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? 4 Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life. 5 For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection: 6 Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin. 7 For he that is dead is freed from sin.
(Romans 6.3-7)

27 For as many of you as have been baptized into Christ have put on Christ.
(Galatians (3.27)

10 And ye are complete in him, which is the head of all principality and power: 11 In whom also ye are circumcised with the circumcision made without hands, in putting off the body of the sins of the flesh by the circumcision of Christ: 12 Buried with him in baptism, wherein also ye are risen with him through the faith of the operation of God, who hath raised him from the dead.
(Colossians 2.10-12)

What I feel it's so important to observe in the Romans and Colossians passages at this point is that Paul says we can only enter into Christ's death by being baptised. Some have said this is symbolic, because of verse 5: 'For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection'. I don't believe it's symbolic however. I believe that when a person is baptised they really do die and when they emerge from the water they really are born again. I've heard people say baptism is a symbol by which they imply that it's not necessary for salvation, which would nullify Christ's words in Mark 16.16. In 1 Peter 3.21, the apostle Peter describes '[the baptism which now saves us]' as the antitype of Noah and his family being saved 'through water' in the ark. This means that the salvation of Noah and his family is actually the symbol (or type) whilst baptism is the 'real' thing (antitype) of which Noah and family's salvation is the symbol. This actually shows that real things that people go through involving real salvation which saves real people's lives can still be a symbol, which means that even if baptism is a symbol, that doesn't mean it has no bearing on people's eternal salvation. The Lord's words in Mark 16.16 assure us incontrovertibly that it does.

according to 1 Cor. 15: 1-4 Paul tell us that we are saved by faith in his gospel (the mystery he receive from Christ himself after his Damascus road experience) of Christ death burial and resurrection no mention of baptism the only baptism is the Holy Spirit baptizing us into the body of Christ. For their is one Lord one faith and one baptism. Water baptism was for the Jew convert from legalism to Christ as their messiah when Peter said in Acts 2:38 he was talking to the Jewish people not Gentiles for Christ himself instructed them not to go in the way of the Gentiles but to the whole house of Israel such was the custom in that day and Paul had to deal with the Jewish believers who came behind him telling his Gentile converts that they had to follow the law and circumcision etc:. I believe that when Christ died his shed blood covered all sins past present and future for them that believe in the finish work of the cross his death burial and the power of his resurrection nothing added to it.

It is not that the apostle Paul impugned the necessity of water baptism, but rather, that particular function or office, which required no special gift, could be performed by others within the Church, perhaps the ὑπηρέτης (cp. Acts 13:5). The apostle Paul had a different and, shall I say, higher calling. He states (1 Tim. 2:7),

For which [testimony] I am appointed a preacher, and an apostle (I speak the truth in Christ, and I do not lie), a teacher of the Gentiles in faith and verity.

Elsewhere, the apostle Paul states that he was "separated for God's gospel" (Rom. 1:1) and had a "holy calling" (2 Tim. 1:9) which was preaching the Gospel and teaching the Gentiles the word of God (2 Tim. 1:10-11 cp. 1 Cor. 1:17).

Logically, if an individual is preoccupied with baptizing convert upon convert, they have no time to preach and teach.

The great commission which Jesus gave to the church put a high value on baptism, and it is very closely associated with salvation:

He said to them, “Go into all the world and preach the gospel to all creation. Whoever believes and is baptized will be saved, but whoever does not believe will be condemned. (Mark 16:15-16, NIV)

In the same way, not only baptism buy out 'confession' of faith is very closely linked with our salvation:

If you declare with your mouth, “Jesus is Lord,” and believe in your heart that God raised him from the dead, you will be saved. For it is with your heart that you believe and are justified, and it is with your mouth that you profess your faith and are saved. As Scripture says, “Anyone who believes in him will never be put to shame.” (Romans 10:9-11, NIV)

Yet when looking closely at the words and using common sense neither baptism or confession has any direct relationship to salvation. Both are external testimonies of the salvation which is by faith only. The Bible does not say 'but whoever does not believe (or is not baptized) will be condemned'. The bible does not say 'For it is with your heart (and your confession) that you believe and are justified'.

The reason why Paul puts baptism as a secondary matter is because his primary interest is in providing eternal life to any that believe and joining sinners into the church by faith in the gospel. To add anything to faith as 'absolutely essential' for salvation and receiving the Holy Spirit, is a concept Paul would never consider. Let others worry about the rest as important as many secondary things are.

1 Corinthians 1:10-14, 16-18 NET I urge you, brothers and sisters, by the name of our Lord Jesus Christ, to agree together, to end your divisions, and to be united by the same mind and purpose. For members of Chloe’s household have made it clear to me, my brothers and sisters, that there are quarrels among you. Now I mean this, that each of you is saying, “I am with Paul,” or “I am with Apollos,” or “I am with Cephas,” or “I am with Christ.” Is Christ divided? Paul wasn’t crucified for you, was he? Or were you in fact baptized in the name of Paul? I thank God that I did not baptize any of you except Crispus and Gaius, (I also baptized the household of Stephanus. Otherwise, I do not remember whether I baptized anyone else.) For Christ did not send me to baptize, but to preach the gospel – and not with clever speech, so that the cross of Christ would not become useless. For the message about the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God.

The ideas in that passage are that each person was boasting about the superiority of their teachings, when all of them were in fact disciples of the same teaching, which was again, an "inferior“ (foolish) teaching. They had absolutely no grounds for boasting, either in terms of uniqueness or superiority.

Baptism is the equivalent of recognising a person can now have table fellowship with God's People. That status must be maintained, just as the observant Jew needed to maintain his clean status and act to rectify any impurity, whether caused accidentally or through carelessness .

1 Corinthians 5:11New International Version (©1984) But now I am writing you that you must not associate with anyone who calls himself a brother but is sexually immoral or greedy, an idolater or a slanderer, a drunkard or a swindler. With such a man do not even eat.

Matthew 18:17 NET If he refuses to listen to them, tell it to the church. If he refuses to listen to the church, treat him like a Gentile or a tax collector.

Acts 8:13, 20-23 NET Even Simon himself believed, and after he was baptized, he stayed close to Philip constantly, and when he saw the signs and great miracles that were occurring, he was amazed. But Peter said to him, “May your silver perish with you, because you thought you could acquire God’s gift with money! You have no share or part in this matter because your heart is not right before God! Therefore repent of this wickedness of yours, and pray to the Lord that he may perhaps forgive you for the intent of your heart. For I see that you are bitterly envious and in bondage to sin.”

In that sense, baptism is an acknowledgement of the suitability of the candidate. The Ethiopian eunuch's request was based on that reasoning. The Corinthian church had distorted that teaching.