Look at the good Thief who died along Christ, he has not been baptised in water, well hard to say about the Spirit, but still he surely entered the Kingdom of Heaven, Jesus told him so.
Neither did he received the Holy Spirit. Catholics would understand this as “baptism of blood.”
The Catechism of the Catholic Church states the following:
*1258 The Church has always held the firm conviction that those who suffer death for the sake of the faith without having received Baptism are baptized by their death for and with Christ. This Baptism of blood, like the desire for Baptism, brings about the fruits of Baptism without being a sacrament.
1259 For catechumens who die before their Baptism, their explicit desire to receive it, together with repentance for their sins, and charity, assures them the salvation that they were not able to receive through the sacrament.
1260 "Since Christ died for all, and since all men are in fact called to one and the same destiny, which is divine, we must hold that the Holy Spirit offers to all the possibility of being made partakers, in a way known to God, of the Paschal mystery."63 Every man who is ignorant of the Gospel of Christ and of his Church, but seeks the truth and does the will of God in accordance with his understanding of it, can be saved. It may be supposed that such persons would have desired Baptism explicitly if they had known its necessity.
1261 As regards children who have died without Baptism, the Church can only entrust them to the mercy of God, as she does in her funeral rites for them. Indeed, the great mercy of God who desires that all men should be saved, and Jesus’ tenderness toward children which caused him to say: "Let the children come to me, do not hinder them,"64 allow us to hope that there is a way of salvation for children who have died without Baptism. All the more urgent is the Church’s call not to prevent little children coming to Christ through the gift of holy Baptism.*
Second, I like to add that Jesus said, “On this day, you will be with me in paradise.”
Well, he was not actually on paradise on that day. When they did died, Jesus for three days preached to the dead and the thief was one of them. They were not in heaven because heaven was not open yet.
The Patriarchs and the Holy saints of the OT before Jesus Christ coming, were in a waiting place. The Creed states that Jesus descended into the dead and on the third day, he rose again.
Let me continue, during those 2 days in place of the dead, the thief was there. Jesus went to preached and open the Gates of Heaven, and brought everyone from Hades up into heaven, like Adam, Eve, Abraham, Moses, and Patriarchs.