As nobody's judgement has yet occurred, no, I can't show an example of a person who has saving faith in the NT.
Stephen would be a good bet though.
Let's study the process of salvation.
God sends people into crisis so that they can see their situation. God sent Joseph and Israel into Egypt by creating (!) a famine so that her situation of serving mammon is shown it its extreme manifestation: she is working for treasure that rusts and perishes.
Israel cries out for deliverance, a change.
God sends Moses who tells Israel to come out of Egypt. To convince her that God can change things for the better, Moses uses the signs and wonders he had been given.
Israel leaves Egypt and follows God. God can feed Israel but He intentionally causes a food and water shortage. When they are alarmed, God provides these necessities, using signs and wonders. This is so they will stop working for treasure that rusts and serve Him for treasure that never perishes, by becoming a blessing to the world. Be born again. This is what Israel has been created for.
From this we see that baptism, the agreement to leave mammon, leads to God demolishing all the things that holds a believer captive to the world. Any reasonable person would have been convinced, and repented in ashes for doubting God, if they had seen the miracles that had been performed in her, but Israel was scared about resigning from her job in Egypt, and becoming totally dependent on God. Out of a million Jews over 20, only Joshua broke away cleanly, and decided to depend only on God, just like the lilies of the field depend only on God, and are dressed even better than Solomon. He really was born again, had a new mindset.
Although they drank and ate from the same spiritual source, Christ the Rock, what they saw did not benefit them, and God was not pleased with them and their bones littered the wilderness of Sinai.
These are similar to the patterns seen in the lives of Abraham, Moses, Peter with positive results and Korah, Judas, Ananias and Sapphira, etc with negative outcomes.
Let’s examine the case of the thief on the cross.
He knew about Jesus: that he was innocent, that he would come into His kingdom, that He would reward those loyal to Him. Apparently he would have learnt this before he was crucified: back in the prison, or further back when he was an active thief. Whether he became a follower or wanted to become a follower, he was arrested, and it didn’t make a difference to the authorities.
Did he leave Egypt? Egypt is selfish living. He did not join in the mocking of the others who were pandering to the relief they got by cursing everybody they could see, who got selfish pleasure from rebuking.
Did he switch to serving God for treasure that lasts? He spoke good things about Jesus, which is what the criteria was for those who were for God.
Mark 9
38John said to Him, “Teacher, we saw someone else driving out demons in Your name, and we tried to stop him, because he does not accompany us.” 39
But Jesus replied, “Do not stop him. No onewho performs a miracle in My name can turn around and speak evil of Me. 40For whoever is not against us is for us.
It seems that the thief had saving faith, but the New Covenant is a superior covenant.
What did the thief lack? Was it justifying faith or sanctifying faith or glorifying faith?