As Christians, we live, not naturally, but supernaturally. The Holy Spirit lives in us to lead us, guide us, love us and transform us. In 1 Thessalonians 5:19 it says:
"Do not quench the Spirit."
I was thinking about this passage and it is clear that we
CAN put out the fire of the Holy Spirit in our lives. Unconfessed sin is like pouring water over the fire of the Spirit, especially grievous sin. Our lives were meant to be lived knitted to the Spirit. He is the Advocate promised by Jesus. Nothing separates us more from God than sin...unconfessed sin. Even venial sin gradually begins to harden our hearts and leave us less open to the inspirations of the Spirit. Verse 22 goes on to say:
"Refrain from every kind of evil."
That a big request. EVERY kind of evil. Lack of charity, lies, unjust anger [let's face it - most anger is unjust]. This is why regular confession is important. Ask the Holy Spirit for light and confess your sins. I go to the Sacrament of Reconciliation about once a month on average and I also ask forgiveness immediately during the course of the day if I've noticed I have sinned. This seems to keep the Holy Spirit shining brightly in my soul. Confession pleases Him. Prayer helps, too.
"Lord who hast mercy upon all, take away from me my sins, and mercifully, kindle in me the fire of thy Holy Spirit. Take away from me this heart of stone, and give me a heart of flesh, a heart to love and adore Thee, a heart to delight in Thee, to follow and to enjoy Thee, for Christ's sake. Amen"
[I am not sure which saint wrote this prayer, St. Gregory maybe?]