Stealing is usurping other people's property without their consent and without intending to return it or pay for it. Armed robbery, a more serious form of stealing involves forcefully taking away things that belong to others through threat and violence. If a child takes away anything (money or materials) from his parents without their consent, it's stealing. Failure to pay for goods and services rendered for you also amounts to stealing.
When we do not restore what we borrowed or pay back debts and dues, it's same as stealing. When you fail to pay tithes and offering, it's equal to pilfering.
Do you have anything in your custody that does not belong to you? You should know by now that that's stealing, you have to make necessary restitution by returning any stolen materials in your custody to the rightful owner's. Remember no thief will make it to heaven.