The bible tells us to resist the devil and he will flee from us. But it also reminds us that he will eventually come back. Satan is patient and looks for opportune times to attack us, times when we are spiritually weak and vulnerable. The bible describes him as a roaring lion seeking out who he can devour. So, we need to be on our guard especially when we are weakened. Luke chapter 4 verse 13 says:
"When the devil had finished all this tempting, he left him until an opportune time."
This is referring to when the devil tempted Jesus in the desert after 40 days of fasting. In that moment, Jesus used scripture to fend off the devil. He used his faith as a shield to extinguish the flaming arrows of the evil one, and the words directly from scripture to parry every blow from Satan - kind of like how the bible describes our faith and the word of God in Ephesians 6. Satan is real. Jesus knows it and we should too. He attacks us when we are weak, like a lion looking to thin out the herd. And even when we fend him off, he will always look for an opportune time to come back. And since we know this we should always be on guard and recognize the signs of his attacks.
When we struggle in our walk or circumstances attack our faith or our joy, we often times write it off as bad luck or we may even go as far as to blame God. But might I suggest that it could possibly be Satan? A discerning believer can see his attacks for what they are, and a strong believer, can combat them with the weapons that God gave us - the words and promises of the bible supported by our faith in the one who wrote them. Satan has no power over a believer except what we give him. Remember to always lean on Christ. When you struggle, cry out to him and remember what he promised in his word. He will never leave you or forsake you. And when you are tempted, he will always provide a way out.