It is meaningless to offer your life as a substitute for others. Christ has already done so, and anyone else offering their life for the sake of others is implying that Christ's perfect sacrifice is not sufficient.
However, it is commendable to have those feelings which would tempt you to volunteer your life for the sake of others. And there is scriptural warrant for believing so. All Christians should aspire to have such feelings. And until we have such feelings we fall short of the love that God wishes us to have for others.
Another answer, of Paul Chernoch, quotes the passage:
For I could wish that I myself were accursed from Christ for my brethren, my kinsmen according to the flesh.. (Romans 9:3)
It is obviously true that the Apostle Paul is speaking only hypothetically, but nevertheless, he means with total sincerity every word he is saying (Romans 9:1-2).
And then, of course, he is speaking under the inspiration of the Holy Spirit.
And then, he is speaking as one full of the Holy Spirit. I doubt such feelings are genuinely possible apart from the fullness of the Holy Spirit.
Are we going to say that Paul's language, and heart-felt desire is not commendable? That would be absurd.
Everything Paul writes and does from the time of his conversion was commendable.
Paul is our pattern Christian: Paul is the exemplar that every Christian should be aspiring to imitate. One might argue that Christ himself is our pattern which is obviously true. The excuse we have for not being the same as Christ is that our Lord Jesus Christ is "God manifest in the flesh" (1 Tim 3:16): how can a sinner like me possibly hope to be like him? I have a perfect excuse for not being like Christ.
But Paul is different; Paul is a sinner like you and me. We have much less of an excuse if we fail to be like him. And so the Holy Spirit has given us an example of how holy a sinner can become, and that example is the Apostle Paul.
And so in Paul's writings the Holy Spirit inspires Paul to write such words as
Wherefore I beseech you be ye followers of me. (1 Cor 4:16)
Be ye followers of me, even as I also am of Christ. (1 Cor 11:1)
Brethren, be followers together of me, and mark them which walk so as ye have us for an ensample. (Phil 3:17)
Those things, which ye have both learned, and received, and heard, and seen in me, do: and the God of peace shall be with you. (Phil 4:9)
And ye became followers of us, and of the Lord... (1 Thess 1:6)
For you yourselves know how ye ought to follow us: for we behaved not ourselves disorderly among you... to make ourselves an ensample unto you to follow us. (2 Thess 3:7..9).
In other English translations the word "imitate"/ "imitator" is used instead of "follow"/ "follower".
There are too many verses urging the reader to imitate Paul to ignore: the inescapable conclusion is that the Apostle Paul is our model Christian, our Exemplar Christian precisely because he is our Exemplar with a sinful nature.
And so it is a commendable thing to follow all the things revealed in Scripture concerning the Apostle Paul subsequent to his conversion.
So it is a commendable thing to wish I myself were cut off/accursed for the sake of others.