Paul certainly based what he taught on what a person can understand by them using their God-given intellect:
"And Paul, as his manner was, went in unto them, and three sabbath days reasoned with them out of the scriptures" (Acts 17:2).
If you base your beliefs on the feelings which come from your heart consider what is said here:
"The heart is deceitful above all things, and desperately wicked: who can know it?" (Jer.17:9).
You are making a huge mistake if you abandon your reason and logic. The LORD Himself said:
"Come now, and let us reason together, saith the LORD: though your sins be as scarlet, they shall be as white as snow; though they be red like crimson, they shall be as wool" (Isa.1:18).
Those who base their beliefs on their feeling which come from their hearts are spoken of here:
"There is a way that seemeth right unto a man, but the end thereof are the ways of death" (Prov.16:5).