Here are some excellent quotes from Watchman Nee on assurance of salvation. They are from the Collected Works of Watchman Nee, The (Set 1) Vol. 02: The Word of the Cross, Lesson 11: The Assurance of Salvation (you can search for them here):
First of all, Nee affirms that everlasting life is a present possession. That means we do not have to hope that we have it, but can know that we have it:
“The Bible teaches us that being saved is a present matter. When we believe, we receive eternal life. Once we believe, we receive. There is no need to wait or to hope. Salvation is not something that happens after death, but is a present matter. Since believers are already saved (John 5:24), unbelievers are already condemned (John 3:18).”
Nee is also clear that the Bible teaches nothing less than complete assurance of salvation.
“Every believer can know whether or not he has eternal life. Men often think, ‘We can only hope that we are saved, and we can only know if we are saved after we die or at the time of judgment.’ This is not the teaching of the Bible. The Bible teaches that a man can know whether or not he has eternal life in this age.”
Nee is also adamant that assurance of salvation is based on Jesus’ promise of eternal life, not on our feelings or behaviors:
“The Bible also tells us that he who believes has eternal life, is justified, has peace, and is saved. We only need to ask ourselves whether or not we have believed into the Lord Jesus as our personal Savior. If we have not believed, we will perish. If we believe, we spontaneously are a person who has eternal life. ‘He who believes has eternal life’ (John 6:47). When we believe, we have eternal life. We know that we have eternal life not because we think or we feel that we do, but because God tells us so. Since we are saved and have received God’s grace, we should not continue in sin (Rom. 6:1-2).”
I plan on writing a journal article on Watchman Nee’s doctrine of assurance. Living Stream Ministries has made all of his writings available online.