I wonder how Abraham felt as he was walking up that mountain with Isaac? God had spoken directly with him and told him to go, but the Bible never says that God kept speaking to him all the way up there. It was a pretty incredible thing that God had asked Abraham to do; I can't imagine him not having a doubt or two along the way in a journey of over three days. Then again, just because I can't imagine it doesn't mean it's not true; the Bible doesn't often tell us the internal dialogue of the characters like modern fiction often does. Usually the Bible reports events as a third person observer.
So we don't really know what Abraham was thinking; we only know that when Isaac asked him what was going on, Abraham said something that was actually a little different from what God had said. Whether he was saying that to deceive Isaac, or whether he had deceived himself, or whether he actually had some revelation from God about the situation over the course of those 3+ days, we don't know. What we do know is that what actually happened in the end resembled what Abraham had said more than what God had said! Figure that one out!
So did Abraham feel some deep-down inner confidence every step of the way? Maybe. The Bible certainly sets him up as a giant of faith, so maybe his confidence was different from mine. But what I know from how my life generally works is that I hear from God, I believe God's words and choose to follow His instructions, but then things don't happen immediately. Things in this lifetime take time. For Abraham it took three days and a little more; often in our lives things can take weeks, months, or even years. And I'll freely admit that during my "three days" (however long those "days" may be), I don't always feel the power of God's instructions and/or promises about my situation. Sometimes I just feel sort of... indifferent.
Does that mean I'm not in faith? You know, I don't think so. I think that as long as I am still on track to do what God has instructed me to do, I'm still acting in faith. Maybe Abraham said what he did to Isaac in order to try to convince himself that everything was going to be okay. After all, all of his hopes and dreams were hinging on Isaac as his only legitimate son. Who knows? What we do know is that Abraham continued to put one foot in front of the other foot, all the way to the mountain where he had been commanded to put all of his dreams for the future to death. And when he got there, God made a way for him.
So maybe I'll just keep walking!