Through the Pentecost novena, the Lord tries to help us realize that we need the Holy Spirit more than we need to breathe. Only by the Holy Spirit can we overcome the world, the flesh, and the devil — the three principal enemies of Christians.
The world hates us for living and sharing God's word (Jn 17:14; see also Jn 15:18). "Savage wolves will come among" us (Acts 20:29; see also Mt 10:16). Other Christians will distort the truth and try to lead us astray (Acts 20:30). Only by the Holy Spirit are we protected from being deceived, brainwashed, and enslaved by the world.
Life in Christ entails hard work and an emphasis more on giving than on receiving (Acts 20:35). However, we are naturally selfish. Only by the Holy Spirit will we crucify the passions and desires of the flesh (Gal 5:24) and be unselfish enough to love.
Satan "is prowling like a roaring lion looking for someone to devour" (1 Pt 5:8). He hates us (see Jn 17:15), is much more powerful than we are, and is determined to damn us forever. How can we overcome him? "Not by might, not by power, but by My Spirit, says the Lord" (Zec 4:6, our transl).
The choice is life in the Holy Spirit or a living death in the evil spirit (see 1 Jn 3:14). We need the Holy Spirit. How much do you want the fullness of the Spirit?