HeadFaith is necessary for HeartFaith.
HeadFaith enables a person to give the correct intellectual response about what they Believe 'in their head'.
HeartFaith manifests through a changed Life.
What we Believe in our head to be True has value but no Power.
It is from the abundance of the Heart that the mouth speaks. Luk 6:45
As a person thinks in their Heart so are they. Pro 23:7
A person who has HeadFaith but no HeartFaith may never share their Faith with another person.
A person with HeartFaith will consistently Speak of their Faith because it is in their Heart.