Your first claim needs backing. We can make decisions either with our mind or with out heart, so to speak - or with both.
Head vs Heart: How Decision-Making Processes Influence Lives & Careers
There is nothing automatically insincere about making decisions with logic rather than with emotions.
Who made this about making decisions between this job or that job, using your emotions or your cognitive faculties to reason a list of pros and cons, as opposed to your emotions driving you? That really is dealing with something else outside what we are addressing here.
More appropriately would be this analogy. You see a group of violent teenagers kicking an old lady laying on the ground. In your heart of hearts, you know this is terribly wrong. But someone tells you this is God's will, and they show you a verse from scripture that they interpret for you that justifies their evil actions. Now, because you are friends with the group they are part of, and are being told you should not object to this, because if you were a true servant of God, you would see God has a purpose behind this, and that this should be seen as justice, truth, and goodness instead, you are faced with a dilemma.
Now, you have a real conflict between what your soul knows to be inherently wrong, and being told this is inherently good by those who you wish to respect and follow. Who should you believe in this case? Absolutely, you should go with the witness of your heart, and not let reason be twisted and manipulated into rationalizing away and obvious evil and calling that good! If you do sever your heart that way, you will become jaded, and callused, and spiritual dead.
1 Timothy 4:2 speaks of those, "
whose consciences have been seared as with a hot iron". That's what I mean by dissociation. That's what I mean by not listening to your heart. That is way beyond the reason vs. emotions argument in decision making processes. It has to do with your character and your soul.
Now apply all of that to hearing about how God is Love, and Grace, and Compassion, and then hearing about the flames of hell he sends those who don't convert to the right religion? Now you either are fine murdering and torturing others, or you aren't but turn a blind eye away from it and deny your own soul, and try to rationalize it away. That is what we are talking about.