The star's son Jett died two years ago after suffering a seizure. He was just 16. But Travolta, 56, said that welcoming the new baby in November has provided him and wife Kelly Preston with a new source of happiness.
He told Hello, 'It's been uplifting, especially when he smiles at me and seems contented in my arms.
'He's given the house a renewed spirit and purpose. He's brought us a new beginning and his presence has brought joy to all the people who have wanted the best for us.
'Like Jett, he definitely looks like his daddy, but every day he changes and often we can see his mother in him.'
Kelly added that nothing makes her happier than being a mother, and that the three-year struggle to conceive has made her even more grateful for her family.
She said, 'We tried for three years and feel blessed that it finally happened. It's one of the most fulfilling things a person can experience in life and I have had the joy of experiencing it with three amazing children. Being a mother makes me the happiest.'