You are wrong, Satmer.
There are definitely Mitzvos Aseh that we must perform in our hearts, and Mitzvos Lo Saseh that one can ch”v be “over” in one’s heart.
We are obligated to serve HKBH with all the gifts He has given us: our bodies, our voices, our hearts and minds, and all our talents and belongings.
I’ll leave it to you to do the research and clarify which Mitzvos are performed in our hearts. It would be a terrible shame to omit this part of our Avodah. Challenging as it may seem, we have been instructed and informed that the performance of all Mitzvos is within our reach although we are just human.