"Be ye angry, and sin not: let not the sun go down upon your wrath", Ephesians 4:26-27. "
Once you have heard the truth in your ear and you know it in your heart then Satan will change tactics. At this point, the word has been firmly planted into the soil of your heart and is deeply rooted. So the only war to stop the seed from bearing fruit is to contaminate the soil with weeds to try and choke the word. In practical terms, Satan will look to drive you into doubt and unbelief, to make you ineffective in the Word that you have received. This is why the scripture tells us to 'get angry'. The instruction is not to get angry at people. They only act the way that they do because of their unbelief. No, our anger should be directed at the devil, along with the doubts and unbelief that he is trying to sow in your heart to make you unfruitful. The scripture tells us to never let the sun go down on this type of anger, i.e. never let up on the Devil.
"Ye are the salt of the earth: but if the salt have lost his savour, wherewith shall it be salted? it is thenceforth good for nothing, but to be cast out, and to be trodden under foot of men.", Matthew 5:13.
The message about anger is linked to that of zeal. It is difficult to do anything for the Lord without zeal. While it is true that zeal without knowledge can do a lot of damage to the kingdom; zeal with knowledge can do a lot of damage to the devil. Jesus describes a believer without zeal as "good for nothing" because the devil will always talk them out of the blessings of god and they will be unfruitful. So we do not bear fruit by taking a passive stance with the devil and accepting all of the doubt and unbelief that he suggests to us. We actively reject these thoughts and refocus our minds back on the blessings that GOD has spoken to us.
" Submit yourselves therefore to God. Resist the devil, and he will flee from you. ", James 4:7
This concept of resisting the devil is captured here in James, but we are told to resist the devil in many places in the scripture. The word for resist used here is "anthistemi", which means to hold one's ground and refuse to be moved. We are already blessed in Christ Jesus and only need to stand in faith in this blessing, but the devil wants to push back against the blessing by invading our minds with doubt and unbelief. So we should take any anger that we feel and focus it all on the devil, being zealous to protect the Word that GOD has given to us. By actively resisting the devil and his lies, we will bear the fruit that GOD intends for us to have.