Your sword of the Spirit is the word of God. This is your offensive weapon. It is what Jesus used when tempted by the devil in the wilderness. Jesus is our model, so when He does it, so should we. “It is written.” Jesus said it three times to the devil. He didn’t make fancy arguments, He just quoted scripture and left it at that.
But notice that the devil quotes scripture as well. If you are the Son of God, throw yourself down. For it is written, He shall give His angels charge over you. In their hands they shall bear you up lest you dash your foot against a stone. (Mat 4:6) (Apparently, at the beginning of Jesus’ ministry, the devil was unsure of who Jesus was. Later on, the demons all knew Him by sight.) Just knowing scripture doesn’t make a response right. It depends on who says it and how it’s said. When the devil quotes scripture, you know it can be manipulated out of context.
Allow the Holy Spirit to bring scripture to mind during the times you need it. That’s when it’s vital and dynamic to the situation at hand. That’s when your sword becomes dangerous and your armor complete. But for that to happen, you have to get that Word into your head. Read the Bible daily.