Deuteronomy 29:4 But to this day the Lord has not given you a heart to understand or eyes to see or ears to hear. ESV

In worldly terms perception is defined as awareness thru the exercise of the senses. Touch, smell and any system that reports to the brain even beyond that of hearing and seeing are all involved in perception. It is the brain that receives the data input and does the analysis which establishes your reality. So why is God making reference to the heart?

Mark 2:8 And immediately when Jesus perceived in his spirit that they so reasoned within themselves, he said unto them, Why reason ye these things in your hearts?

Psalm 44:11 Shall not God search this out? for he knoweth the secrets of the heart.

The emphasis here is over the actions of men, which we see, and the speech of men, which we hear, which belie what is truly in their hearts. How are you to know by faith what is God’s will for you in any of these situations if you rely only on worldly senses? To walk in the Spirit we must be willing and able to allow faith to act as our guide and not our worldly senses.

Hebrews 5:14 But strong meat belongeth to them that are of full age, even those who by reason of use have their senses exercised to discern both good and evil.

The key here is “by reason of use”. You must exercise your faith, take it out for a walk, in order to experience how it works apart, separate from the other senses.

Faith doesn’t sit around waiting for God to do something. It needs exercise.