Hi Marlene,
We can see from the beginning of this chapter that Paul is trying to persuade the believers/brothers, that there is a resurrection from the dead.
1Co 15:3 For I delivered to you first of all that which I also received, that Christ died for our sins, according to the Scriptures,
v. 4 and that He was buried, and that He rose again the third day according to the Scriptures;
Now as you read these scripture up to verse 29, you can see Paul is explaining to them that since Christ was raised, that they too can have faith that they will be raised.
The resurrection of the dead does not seem to be believed by most at that time.
1Co 15:12 But if Christ is proclaimed, that He was raised from the dead, how do some among you say that there is no resurrection of the dead?
v. 13 But if there is no resurrection of the dead, neither has Christ been raised.
v. 14 And if Christ has not been raised, then our proclamation is worthless, and your faith is also worthless.
v. 15 And we are also found to be false witnesses of God, because we testified of God that He raised Christ; whom He did not raise if the dead are not raised.
v. 16 For if the dead are not raised, then Christ is not raised.
v. 17 And if Christ is not raised, your faith is foolish; you are yet in your sins.
1Co 15:18 Then also those that fell asleep in Christ were lost.
v. 19 If in this life only we have hope in Christ, we are of all men most miserable.
v. 20 But now Christ has risen from the dead, and has become the firstfruit of those who slept.
v. 21 For since death is through man, the resurrection of the dead also is through a Man.
v. 22 For as in Adam all die, even so in Christ all will be made alive.
v. 23 But each in his own order: Christ the first-fruit, and afterward they who are Christ's at His coming;
1Cor. 15:29 Otherwise, what will they do, those being baptized on behalf of the dead? If
the dead are not at all raised, why indeed are they baptized on behalf of the dead?
So in verse 29 you can see Paul is still trying to convince them that, "those being baptized on behalf of the dead?" and I believe "the dead" this is talking about is Christ.
Rom 6:3 Do you not know that as many of us as were baptized into Jesus Christ were baptized into His death?
v. 4 Therefore we were buried with Him by baptism into death, so that as Christ was raised up from the dead by the glory of the Father; even so we also should walk in newness of life.
v. 5 For if we have been joined together in the likeness of His death, we shall also be in the likeness of His resurrection;
Paul goes on to say, "If the dead are not at all raised," or if Christ was not raised, "why indeed are they baptized on behalf of the dead (Christ)?" So if they do not believe in a resurrection of the dead, Paul is saying it would be useless to be baptized into Christ's death, "on behalf of the dead," if He was not resurrected.
Paul is saying if they do not believe that Christ was raised, then why would anyone be baptized on behalf of someone who they think is still dead.
It is not Christ's death that saves us, it is the hope of the resurrection.
Rom 5:10 For if when we were enemies, we were reconciled to God through the death of His Son, much more, being reconciled, we shall be saved by His life.
That's the way this verse 29 looks to me
mercy, peace, and love
Kat