First of all we are talking about cosmology. the structure of reality. Atheists, at least Dawkins, Dennett, & Co., claim that reality is solely physical- matter and energy. This precludes the existence of the spiritual and the rational. Fair enough.
However the way to test this theory is to find an error. If one says that this precludes God because it says that there is no spiritual aspect to reality, and this is not true, because there is a spiritual aspect of reality, then the theory is wrong.
Second, Love is not an emotion. Love is a spiritual relationship. It is not physical, so it blows a hole on the claim that reality is purely physical, unless it is not real or imaginary, which it is not.
Third, Disproving the claim of New Atheism that Reality is strictly physical does not per se prove the fact that God exists as I say above. However atheists have made the claim that atheism must be true because there is no proof that God exists, which I have demonstrated is false, so it is very tempting to go the other way.
Fourth, the existence of love does not give people per se knowledge of God, but it does give them the possibility of knowledge of God and Reality. Anyone and everyone can know love and can love others and love God. This is spiritual knowledge.
If knowledge of reality must be through scientific knowledge, then everyone would need to receive a college education in science to understand how life works. Spiritual knowledge is not elitist knowledge. It is open to all.