In "The Hour of Truth", by Percival Wilde, Mr. Baldwin's attitude only changes by getting from frustrated to more frustrated as he sees the effects of greed and what the love for money can do the people that he cared for the most: His family, and his boss.
However, Mr. Baldwin never changes his attitude in terms of being dishonest. Maybe at the beginning of the play, when Mr. Gresham asks him to lie on his behalf, Mr. Baldwin may have seen himself placed between a rock and a hard place. The shock of the situation may have made him seem as if he would genuinely consider to accept the bribe. However, all he really was thinking is how to act in the most intelligent way possible so to not affect anyone else around him.
In the end, he still stuck to his morals and chose to not accept the bribe. After that, he became the bigger man: He remained true to himself and got rewarded for that by getting a better job at a different bank. Hence, it was the good of the man what made all the difference.