When we were baptized, the Church specifically prayed for us to be delivered from the evil one. Jesus, Who is stronger than Satan, the strong man, has freed us (Lk 11:22). Jesus warns us that the evil one will return and re-enter our lives with a second and much worse wave of demons, if conditions are favorable for the evil one's return (Lk 11:24-26). Therefore, we must be clothed with Christ (Gal 3:27) and filled with the Holy Spirit (see Acts 2:4). Then when the evil one returns, he will be repelled. In other words, we must live our Baptisms as true, totally committed disciples of Jesus, or we will be re-visited by many demons.
The alternative to discipleship is not merely lukewarmness; it is being demonically manipulated in vicious, degrading ways. Thus, "when men have fled a polluted world by recognizing the Lord and Savior Jesus Christ, and then are caught up and overcome in pollution once more, their last condition is worse than their first. It would have been better for them not to have recognized the road to holiness than to have turned their backs on the holy law handed on to them, once they had known it" (2 Pt 2:20-21). Therefore, let us live our Baptisms and devote ourselves "to the apostles' instruction and the communal life, to the breaking of bread and the prayers," (Acts 2:42) and to helping others also be faithful to their baptismal covenants.