A dying man asked a dying man for eternal life; a man without possessions asked a poor man for a kingdom.…In the divine plan it was a thief who was the escort of the King of kings into paradise. If our Lord had come merely as a teacher, the thief would never have asked for forgiveness. But since the thief’s request touched the reason of his coming to earth, namely, to save souls, the thief heard the immediate answer. “I promise thee, this day thou shalt be with me in paradise” (Luke 23:43). It was the thief’s last prayer, perhaps even his first. He knocked once, sought once, asked once, dared everything, and found everything. When even the disciples were doubting and only one was present at the cross, the thief owned and acknowledged him as Savior.
Source: Life of Christ