I

Since people began to believe in God, they've harbored many incorrect intentions. When you're not practicing the truth, you feel all your intentions are correct, but when something happens to you, you will see that there are many incorrect intentions within you. When God makes people perfect, He causes them to realize that there are many notions within them that are obstructing their knowledge of God. When you recognize that your intentions are wrong, if you're able to stop practicing according to your notions and intentions, and are able to bear testimony to God, and stand firm in your position in all that happens to you, this proves that you have rebelled against the flesh.

II

When you rebel against the flesh, there will inevitably be a battle within you. Satan will try and make people follow it, will try and make them follow the notions of the flesh and uphold the interests of the flesh—but God's words will enlighten and illuminate people within, and at this time it is up to you whether you follow God or follow Satan. God asks people to put the truth into practice mainly to prune the things inside them, to prune their thoughts and notions that are not in line with God's intentions. The Holy Spirit touches people in their hearts and enlightens and illuminates them. So behind everything that happens is a battle: Every time people put the truth into practice, or put the love of God into practice, there is a great battle, and though all may seem well with their flesh, in the depths of their hearts a life-and-death battle will, in fact, be going on—and only after this intense battle, after a tremendous amount of reflection, can victory or defeat be decided. It's because of this battle that people endure suffering and refinement; this is true suffering. When the battle comes upon you, if you are able to truly stand on God's side, you will be able to satisfy God. While practicing the truth, it is inevitable that one will suffer inside.

from The Word, Vol. 1. The Appearance and Work of God. Only Loving God Is Truly Believing in God