To emphasize the meaning of the verb in the Present Simple Tense, it is possible to use the auxiliary verb do/does also in the affirmative sentence. The sentence then does not change its meaning, it only strengthens it.
I love her.
I do love her.
In oral expression, the main emphasis in the sentence is on the auxiliary verb do/does.
You do look nice today.
He does believe you!
Similar strengthening can be given to imperatives by adding the same auxiliary verb:
Come with us.
Do come with us!