When the time comes to sacrifice all, it is neccesary to not fall for the temptation that we need not sacrifice all for the good news of Him who did the same and so follow in His example; justifying that need with the needs of the moment- that is, the needs of the flesh. Grace, we may or may not know, can be used by us against us when, as temptation arises, we allow our hearts to deceive us and by it use grace against us in our duty to resist sin and then allowing for the grace of God to rescue us after we do sin. I am not saying that grace is a bad thing, but God cannot be tempted, and we, if we allow ourselves to be deluded by temptation to sin against the will of our Father, knowing that we can and will be forgiven, can be led to a place where we abuse the grace of God. And this is not a place where we should abide. Jesus, knowing he would endure the sin of the world and pain of excrutiating death, among other spiritual pains, knew in fact he could call the angels of heaven to rescue Him, but rather entered into a place where prayer was needed to absolve Himself of the notion that He might sidestep that which was required. It was prayer that keep Him focused on the will of the Father, and that will led Him to suffering on the cross.This, in essence, was partial of what He spoke to His disciples, and might be one of the primary lessons to be learned by His words and example.