Jesus could have meant Heaven. Or he could have meant the place where Moses, Elijah and all the other saints were prior to Jesus' opening the gates of Heaven.
Regardless, baptism is normative as can be seen from the Acts of the Apostles:
Acts 191While Apollos was at Corinth, Paul took the road through the interior and arrived at Ephesus. There he found some disciples 2and asked them, "Did you receive the Holy Spirit when[1] you believed?" They answered, "No, we have not even heard that there is a Holy Spirit." 3So Paul asked, "Then what baptism did you receive?" "John's baptism," they replied. 4Paul said, "John's baptism was a baptism of repentance. He told the people to believe in the one coming after him, that is, in Jesus." 5On hearing this, they were baptized into[2] the name of the Lord Jesus. 6When Paul placed his hands on them, the Holy Spirit came on them, and they spoke in tongues[3] and prophesied. 7There were about twelve men in all.
Romans 61What shall we say, then? Shall we go on sinning so that grace may increase? 2By no means! We died to sin; how can we live in it any longer? 3Or don't you know that all of us who were baptized into Christ Jesus were baptized into his death? 4We were therefore buried with him through baptism into death in order that, just as Christ was raised from the dead through the glory of the Father, we too may live a new life. 5If we have been united with him like this in his death, we will certainly also be united with him in his resurrection. 6For we know that our old self was crucified with him so that the body of sin might be done away with,[1] that we should no longer be slaves to sin-- 7because anyone who has died has been freed from sin.
Q: In Luke 23:43, Jesus tells the good thief: "Truly, I say to you, today you will be with me in paradise." Does this mean he went to heaven on Good Friday?A: No. There are a couple of ways of taking this verse. How it is taken depends on whether the temporal clause "today" (Greek, semeron) modifies what comes before it or what comes after it in the sentence. There is no punctuation in the original Greek--all of that is added by the translators--and the sentence can be punctuated one of two basic ways with regard to the word "today," depending on which part of the sentence "today" is supposed to modify. The two basic ways of punctuating it are:
1. Truly, I say to you, "Today you will be with me in paradise."
2. Truly, I say to you today, "You will be with me in paradise."
I have added quotation marks to the promise Jesus is making in order to make the distinction of meaning clearer, but the important thing is the position of the comma. If the comma comes before "today" then Jesus is promising the thief he will be in paradise that day. If the comma comes after today then Jesus is emphatically calling attention to when the promise is made ("today"), but what he is promising is that the thief will end up in paradise and not saying anything about when the thief will end up there. Either one of these is possible given the Greek grammar.
If the first is taken then we must conclude that paradise was where Jesus went when he died. Since he did not go to heaven when he died, but rather he descended to the dead (1 Peter 4:6), paradise at that time would have been in the place of the righteous dead, which at that time was not in heaven but was a place Jesus' described as "Abraham's bosom" (Luke 16:22). The righteous dead only began going to heaven itself after Jesus opened the gate of heaven to them with his resurrection (CCC 632-635, 1026). For the same reason, we can infer paradise was in "Abraham's bosom" rather than heaven at the time since the good thief would not have gone toheaven as Jesus had not yet opened heaven to the righteous dead.
This speculation is unnecessary, however, if the second interpretation of the sentence is taken and Jesus is simply using the word "today" to emphatically call attention to the promise rather than as a part of the promise.
What I am pointing out is that baptism is not a means of salvation, that is through being Born Again, as stated very clearly by the Lord in John 3:3.
I have no problem with baptism, and as matter of fact, both recommend it and perform it, but only upon those making a decison to be the Lords and after having made that decison, ask to be baptised. At which time, I require the one being baptised to make a confession of faith and to give their testimony as well. A lot differant than the baptism of sprinkeling a bit of water on a sleeping infant who has no idea of what is going on.