The ultimate love of God, that He became a man and died on the cross for you and me. The only thing that we can hope for and the only thing that God will accept. Faith in His son.
I believe in Hebrews 11 type of faith and the faith that James speaks about and the faith of Jesus and the faith of all that the Apostles did and the faith that will have us to read His Every Word and believe it, because He 'is' The Word of God and He said through His Apostles that we are to 'walk even as He walked".
Walking in the Spirit is not 'guessing' what to say or 'guessing what a person is like' or 'guessing' what to say or do ... it's humans admitting that "without Him we can do nothing" and that in our flesh dwells No Good Thing - so we die to our autonomous living by our own minds alone and listen for His Still Small voice to lead, direct and teach His dumb Sheep and all Sheep are dumb and need their Shepherd to survive and not walk off a cliff somewhere and they hear His Voice and Know His Voice and follow His Voice because they know that, as long as they do - they'll be safely in the center of His will and not trying to play God by guessing what others are like and judging their salvation, etc. etc. with dumb sheep brains instead of the Only Omniscient One to guide them along.
We all step out in the flesh at times, but it's not His will that we do - because we get hurt when we're not listening to the Shepherd and letting Him control the action or thought.
We should be growing daily in leaving self behind and being totally dependent on Him to be the guiding Shepherd that He is and listen.
There's a lot of voices trying to get our attention and we can only hear His Voice when we quiet them all, including our own, and know that our Life is depending on doing just that -- more than we know.