For instance, look at the following treatment:
2 > 1
Hence: 2(∞) > ∞
Does it makes sense? Well, of course not! There’s no such thing as something that is twice as infinite as another! Infinity isn’t a number, but just a limit.
Harkening back to the question, notice that we allowed b = a, which means that (b – a) = 0. And thus this step is wrong:
Reminds me that grace is God’s way of loving us infinitely as much as an infinite God can already possibly love.