That Mr Thomas Liao, 30, spends his days helping others in the social work profession is a path he could not have foreseen taking a decade ago. By the age of 20, he was a gangster and a drug trafficker sentenced to 5½ years' jail and 10 strokes of the cane.

The downward spiral of his life was halted when he converted to the Christian faith while serving time in Changi Prison.

He said: "Through my new-found faith, I saw what I did was wicked and meaningless. Selling drugs destroys lives and destroys families."

It was something of a miracle that his own life had come so close to being destroyed but was snatched from the jaws of destruction, all before he turned 30, considering how the odds were stacked against him right from the start.

An only child, Mr Liao was very young when his parents divorced.

He lived with his father, who was also a former convict, although Mr Liao declined to say more about this. His father remarried and he could not get along with his stepmother.

His own mother had ceased all contact with him when he was just 12. He said: "I had an incomplete family and that affected me. I felt I had no one to talk to and no one understood me. Life felt so unfair."

To gain a sense of belonging, he joined a gang in secondary school.

Before long, he had picked up glue-sniffing and was shoplifting items from cheap snacks to more expensive products like toy models, on dares by other gang members.

He said: "You could not be a coward or even your friends would bully you. And I was a defiant kid."

When he was 15, his stepmother had had enough and threw him out of the house. He went to live with an aunt.

In his teens, he was involved in all manner of illegal activities. He peddled pirated DVDs, ran errands for loan sharks and transported contraband cigarettes for his gang bosses. And he sank deeper into his drug addiction, going from glue-sniffing to taking drugs like Ecstasy and Erimin.

At the height of his addiction, he was spending $150 to $200 a day on illicit substances. The trafficking started when he was 19, to feed the habit. It was big money.

Mr Liao said he earned about $10,000 a month and had a few "runners", youths who peddled drugs for him as they could not afford to pay him for their drug supply.

"I couldn't make it in school and the teachers and other students looked down on me," said Mr Liao, who dropped out of the Normal (Technical) stream in Secondary 3. "I wanted them to see that I could be successful, wealthy and powerful by being a full-time gangster."

He was 20 when the police arrested him.

He was petrified, wondering how he would survive behind bars. There was the caning, which he described as a nightmare.

Then came his spiritual conversion. "Getting arrested was a blessing that changed my life. If I didn't get caught, I think I would still be on the streets," he said.

While serving his sentence, he decided to give his studies another shot. It was a challenge as he could barely string together a sentence in proper English. But he managed to pass the N-level examinations and then the O levels, taking the English paper twice to pass it.

He knew he wanted to find a job in the helping profession, and pursued a diploma in social work at Nanyang Polytechnic after his release. He said: "I never did anything good in the past and with this new life, I wanted to help others. It's like paying back for the past."

To his relief, his polytechnic course mates did not judge him but befriended him when he shared his story with them. He worked hard at the course work as he "really wanted to serve the community", and graduated in 2014.

Mr Liao is working as a social work associate at Fei Yue Community Services. His job includes helping poor families apply for financial aid schemes, and co-coordinating a tuition programme for children from disadvantaged backgrounds.

Mr Liao, who is single, said his relationship with his family improved after he was released from jail as he made the effort to "reconnect" with them. He is also studying part-time for a degree in social work at the Singapore University of Social Sciences, so that he can be a full-fledged social worker.

"I'm happy to see that through our work, we can see the lives of others improve," he said. "People have different struggles that may be beyond their control. As long as you don't give up and have hope, I believe one day you can achieve something."

And that is something he really believes. After all, he saw it come true with his own eyes, through his own life.

GENERATION GRIT: Know of a Singaporean aged 35 or below who has shown grit amid life's adversities? E-mail us at stnewsdesk@sph.com.sg