Will a child continue to use a pacifier until I take it away from him?

Not necessarily. Infants may use & abandon a pacifier depending on their degree of attachment & availability of interesting alternatives. I have had kids that never took to one and some that carried one about until preschool.Sudden removal confuses a todler who wonders why they are being punished, or why mommy took my best buddy away. The wounded trust may last a lifetime. Reduce paci time gradually & they toss it.
Usually. Most children will use their pacifiers until it is taken away. You should aim to wean your child by 24 months to limit any interference the pacifier will have with language development. By age 2 children are able to use other forms of comfort such as hug, smile, or reassuring words from their parents. Pacifiers can be weaned at once ('cold turkey') or gradually by limiting their use to bedtime.