POOR
"Blessed are the poor in spirit" (Matt. 5:3).
Being poor in spirit is realizing that one has absolutely nothing. The danger for a believer is that there are too many things in his spirit. Only those who realize that they are poor in spirit can be humble. A believer’s experience, growth, and progress very often become self-valued treasures in his spirit, causing it to lose its poverty. To meditate on one’s gains and pay attention to one’s experiences are very subtle dangers. The believer, however, often does not realize this. What is being poor? Being poor is having nothing. If a believer has the deepest experience and constantly remembers the experience, it is like cargo in his spirit and becomes a snare to him. Only an empty spirit will cause a believer to lose himself in God. A rich spirit will cause a believer to become self-centered. Complete salvation frees a believer out of self and back to God. If a believer retains something for himself, his spirit will immediately turn inward and be unable to "reach out" to be joined in God.
MEEK
"A spirit of meekness" (Gal. 6:1).
This is a very important condition for the spirit. Meekness is the opposite of hardness and stubbornness. God requires a meek spirit of us. An unyielding spirit will often lose the leading of God. A meek spirit can forsake one’s will and obey God in the shortest time. Whoever has a meek spirit can immediately stop, according to the Lord’s leading, without any previous notification from God, even when he is in the midst of utter prosperity in his work. Philip was like this when he was called in Samaria to go to the wilderness. A meek spirit turns freely in God’s hands as God wills. A meek spirit does not know how to resist God and follow one’s own will. God needs such a submissive spirit to accomplish His will.
A meek spirit is not any less important towards man. A meek spirit is a spirit which is like a lamb, a spirit of the cross. "Who being reviled did not revile in return; suffering, He did not threaten" (1 Pet. 2:23); this is a meek spirit. A meek spirit is willing to be wronged. Even though one is protected by the law and able to take revenge, he would by no means use his fleshly arm to redress himself. This spirit, though suffering pain and damage, causes no harm to others. Whoever has such a spirit conducts himself in righteousness but does not demand righteousness from others. He is filled with love, grace, and kindness; therefore, he is able to melt those who are surrounding him.
FERVENT
"Do not be slothful in zeal, but be burning in spirit, serving the Lord" (Rom. 12:11).
The flesh can become enthusiastic for a moment from stimulation or emotion, but this is only temporary and does not last long. Even when the flesh is most zealous, it can still be very lazy because it will only be zealous for the things which suit its will. Its zealousness is merely helped by emotion. It cannot serve the Lord in those things which it dislikes or when it is emotionally cold. The flesh cannot labor with the Lord in continually doing things slowly, step by step, rain or shine. Being "fervent in spirit" is a long-term matter; only then can we always serve the Lord. We should avoid all fleshly enthusiasm. We should let the Holy Spirit fill our spirit and keep our spirit fervent. Then, even when our emotion is cold, our spirit will not become cold and immovable in the Lord’s work.
The apostle’s word in this verse is a commandment. Therefore, our renewed will can choose this. We should exercise our will to choose fervency. We should say, "My spirit desires to be fervent and is unwilling to be cold." When our emotion is utterly disinterested, we should let our fervent spirit control everything, not letting our lukewarm feelings overcome us. Always serving the Lord in singleness is a demonstration of a fervent spirit.
(Spiritual Man, The (3 volume set), Chapter 25, by Watchman Nee)