People are made up of basic "metals" or qualities. The best of them in Jahiliyyah are the best of them in Islam, according to a  hadith of the Prophet. 

Here are two pictures of a noble companion--one during his life in Jahiliyyah and the other after he became a Muslim . 

In Jahiliyyah, this Sahabi was known as Zayd al-Khayl. When he became a Muslim, the Prophet renamed him Zayd al-Khayr. 

The tribe of Aamir were afflicted one year by a severe drought which destroyed crops and vegetation and caused livestock to  perish. So bad was it that one man left the tribe with his family and went to Hira. There he left his family with the words,  "Wait for me here till I return to you." He swore to himself not to return to them until he earned some money for them or died  in the process. 

The man took some provisions with him and walked all day in search of something for his family. At nightfall, he found himself  in front of a tent. Nearby a horse was tethered and he said to himself: 

"This is the first booty." He went to the horse, untied it and was about to mount it when a voice called out to him: 

"Leave it and take your life as booty." He hastily abandoned the horse. 

For seven days he walked until he reached a place where there was a pasture for camels. Nearby was an enormous tent  with a leather dome, signs of great riches and wealth. 

The man said to himself: "Doubtless this pasture has camels and doubtless this tent has occupants." The sun was about to  set. The man looked inside the tent and saw a very old man in the center. He sat down behind the old man without the latter  realizing his presence. 

The sun soon set. A horseman, imposing and well built, approached. He rode his mount erect and tall. Two male servants  accompanied him, one on his right and the other on his left. With him were almost a hundred she-camels and in front of them  a huge male camel. Clearly he was a well endowed man. To one of the servants he said, pointing to a fat camel: 

"Milk this and give the old man a drink." The shaykh drank one or two mouthfuls from the full vessel which was brought to  him and left it. The wanderer went up to it stealthily and drank all the milk in it. The servant returned, took the vessel and  said: 

"Master, he has drunk it all." The horseman was happy and ordered another camel to be milked. The old man drank only one  mouthful and the wanderer drank half of what was left so as not to arouse the suspicion of the horseman. The horseman  then ordered his second servant to kill a sheep. Some of it was grilled and the horseman fed the shaykh until he was  satisfied. He and the two servants then ate. After this, they all slept soundly; their snoring filled the tent. 

The wanderer then went to the he-camel, untied and mounted it. He rode off and the she camels followed. He rode  throughout the night. At daybreak he looked around in every direction but did not see anyone following him. He pushed on  until the sun was high in the sky. He looked around and suddenly saw something like an eagle or a big bird in the distance  coming towards him. It quickly gained on him and soon he saw that it was the horseman on his horse. 

The wanderer dismounted and tied the he-camel. He took out an arrow and placed it in his bow and stood in front of the  other camels. The horseman stopped at a distance and shouted: 

"Untie the camel." The man refused saying how he had left behind him a hungry family in Hira and how he had sworn not to  return unless he had money or died in the process 

"You are dead if you do not untie the camel," said the horseman. The wanderer again refused to do so. The horseman  threatened him once more and said: 

"Hold out the reins of the camel. There are three knots in it. Tell me in which of them you want me to place my arrow." The  man pointed to the middle knot and the horseman lodged an arrow right in the center as if he had neatly placed it there with  his hand. He did the same with the second and third knots. At that, the man quietly returned his own arrow to his quiver and  gave himself up. The horseman took away his sword and his bow and said to him: 

"Ride behind me." The man expected the worst fate to befall him now. He was at the complete mercy of the horseman who  said: 

"Do you think I will cause you harm when you have shared with Muhalhil (the old man, his father) his drink and his food last  night?" 

When the man heard the name Muhalhil, he was astonished and asked: "Are you Zayd al-Khayl?" 

"Yes," said the horseman. 

"Be the best captor," pleaded the man. 

"Don't worry," replied Zayd al-Khayl calmly. "If these camels were mine, I would give them to you. But they belong to one of  my sisters. But stay some days with me. I am about to make a raid." 

Three days later he raided the Banu Numayr and captured about a hundred camels, as booty. He gave them all to the man  and sent some men with him as guards until he reached his family in Hira. 

The above is a story of Zayd al-Khayl as he was in Jahiliyyah recounted by the historian ash-Shaybani. The books of Siyar  give another picture of Zayd al-Khayl as he was in Islam . . . 

When Zayd al-Khayr heard the news of the Prophet, peace be upon him, he made some of his own enquiries and then  decided to go to Madinah to meet the Prophet. With him was a big delegation of his people among whom were Zurr ibn  Sudoos, Malik ibn Jubayr, Aamir ibn Duwayn and others. 

When they reached Madinah, they went straight to the Prophet's Mosque and tethered their mounts at its door. It happened  that as they entered, the Prophet was on the mimbar addressing the Muslims. His speech aroused Zayd and his delegation  and they were also astonished by the rapt attention of the Muslims and the effect of the Prophet's words on them. The  Prophet was saying: 

"I am better for you than al-Uzza (one of the main idols of the Arabs in Jahiliyyah) and everything else that you worship. I am  better for you than the black camel which you worship besides God." 

The Prophet's words had two different effects on Zayd al-Khayl and those with him. Some of them responded positively to  the Truth and accepted it. Some turned away and rejected it. One of the latter was Zurr ibn Sudoos. When he saw the  devotion of the believers to Muhammad, both envy and fear filled his heart and he said to those with him: 

"I see a man who shall certainly captivate all Arabs and bring them under his sway. I shall not let him control me ever." He  then headed towards Syria where it is said he shaved his head (as was the practice of some monks) and became a  Christian. 

The reaction of Zayd and others was different. When the Prophet had finished speaking, Zayd stood up, tall and  impressive-looking in the midst of the Muslims and said in a loud and clear voice: 

"O Muhammad, I testify that there is no god but Allah and that you are the messenger of Allah." 

The Prophet came up to him and asked, "Who are you" 

"I am Zayd al-Khayl the son of Muhalhil." 

"From now on you are Zayd al-Khayr instead, not Zayd al-Khayl," said the Prophet. "Praise be to God Who has brought you  from the hills and dales of your native land and softened your heart towards Islam." Thereafter he was known as Zayd  al-Khayr (Zayd the Good). 

The Prophet then took him to his house. With them were Umar ibn al-Khattab and some other Companions. The Prophet  gave him a cushion to sit on but he felt very uncomfortable to recline thus in the presence of the Prophet and he returned  the cushion. The Prophet handed it back to him and he returned it to him. This happened three times. Eventually, when they  were all seated, the Prophet said to Zayd al-Khayr: 

"O Zayd, no man has ever been described to me and when I see him he does not fit the description at all except you. You  have two characteristics which are pleasing to God and His Prophet." 

"What are they?" asked Zayd. 

"Perseverance and sagacity," replied the Prophet. 

"Praise be to God," said Zayd, "Who has given me what He and His Prophet like." He then turned directly to the Prophet and  said: "Give me, O messenger of God, three hundred horsemen and I promise you that I will secure Byzantine territory with  them." The Prophet praised his fervor and said, "What manner of man are you!" 

During this visit, all those who stayed with Zayd became Muslims. They then desired to return to their homes in Najd and the  Prophet bade them farewell. The great desire of Zayd al-Khayr to work and fight for the cause of Islam, however was not to  be realized. 

In Madinah al-Munawwarah at that time there was an epidemic of fever and Zayd al-Khayr succumbed to it and said to those  with him: "Take me away from the land of Qays. I have the fever of small pox. By God, I shall not fight as a Muslim before I  meet Allah, the Mighty the Great." 

Zayd took the road to his people in Najd in spite of the fact that the fever became more and more intense and slowed him  down. He hoped at least to get back to his people and that they would become Muslims, through God's grace, at his hands.  He struggled to overcome the fever but it got the better of him and he breathed his last on the way before reaching Najd.  Between his acceptance of Islam and his death, however, there was no time for him to have fallen into sin.