You should deliver these lines with both a calm voice and a smiling expression. The way you deliver words along with your facial expressions, has equal weight to the actual words you speak.
You should state these phrases both during bedtime routines, and whenever your child needs comfort. Consistent repetition helps develop strong emotional routines.
When you speak to your child, you should use their name and describe a particular action they performed during the day. Show affection by hugging or cuddling your child to make him feel secure and loved.
Sources:
Psychology Today – The Power of Positive Words for Children
American Academy of Pediatrics – How Bedtime Routines Affect Kids
Child Mind Institute – Helping Kids Cope With Anxiety
Verywell Family – Importance of Bedtime Messages for Children
Raising Children Network – Building Self-Esteem in Children Through Words