My point is Mat 7:21 Not everyone who says to me Lord, Lord will enter the kingdom of heaven but only those who does the will of my Father in heaven. ( Notice the following verses) 22 On that day many will say to me, Lord, Lord did we not prophecy in your name and cast out demons in your name and do many deeds of power in yourname? 23 Then I will declare to them " I never knew you, go away from me, you evildoers."
So even some people did service in the name of the Lord it was still not enough. Obedience to the will of the Father will guarantee entry into the kingdom of heaven.
In Mat 28:19 Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, 20
and teaching them to obey everything that I have commanded you. And remember I am with you always, to the end of the age.
As Jesus said in Luke 10:16, Whoever listens to you listens to me, and whoever rejects you rejects me and whoever rejects me rejects the one who sent me.
Jesus gave instructions to the Apostles and it is the duty of the Apostles to teach everything that the Lord commanded them to do. In John 14:26 But the Advocate the Holy Spirit whom the Father will send in my name will teach you everything and remind you of all that I have said to you. John 16:12 I still have many things to say to you but you can not bear them now, 13 when the Spirit of truth comes, he will guide you in to all the truth for he will not speak on His own, but will speak whatever he hears, and he will declare to you the things that are to come. The Apostle’s teaching is guided by the Holy Spirit so salvation is a continuos process. He who endures to the end will be saved.
But in your point if his repentance is sincere I believe he is saved but if he still lives there is a tendency he will fall away. Adam received the breath of life and yet he fell.
If you really received the Holy Spirit I don’t think you will stop on Acts 2:38 you will definitely do whats on Acts 2:42.