"So I tell you this, and insist on it in the Lord, that you must no longer live as the Gentiles do, in the futility of their thinking. They are darkened in their understanding and separated from the life of God because of the ignorance that is in them due to the hardening of their hearts. Having lost all sensitivity, they have given themselves over to sensuality so as to indulge in every kind of impurity, with a continual lust for more.
"You, however, did not come to know Christ that way. Surely you heard of him and were taught in him in accordance with the truth that is in Jesus. You were taught, with regard to your former way of life, to put off your old self, which is being corrupted by its deceitful desires; to be made new in the attitude of your minds; and to put on the new self, created to be like God in true righteousness and holiness.
"Therefore each of you must put off falsehood and speak truthfully to his neighbor, for we are all members of one body."
I wanted to address the topic of Halloween, but what I wanted to say has already been said, so I'll just refer you to a good link.
Click here to read about Halloween from a Christian perspective.
I will say just a couple things, but please visit the above link to get a better understanding of where I'm coming from on this.
It is easy to view Halloween as a cute time for little kids to dress up and get candy. This is a good way for Satan to blind Christians from what really goes on and prevent them from seriously praying to stop the enemy. Church "harvest parties" or "trunk and treat" (very popular around here) held in order to keep kids safe and off the streets or as a "Christian" alternative are equivalent to handing condoms out to highschoolers because "They're going to do it anyway, might as well be 'safe'." We are called to be "holy and blameless" (Ephesians 1:4) and to "stand against the devil's schemes" (Ephesians 6:11). We are not called to syncretism.
"Be imitators of God, therefore, as dearly loved children and live a life of love, just as Christ loved us and gave himself up for us as a fragrant offering and sacrifice to God. . .
"For you were once darkness, but now you are light in the Lord. Live as children of light (for the fruit of the light consists in all goodness, righteousness and truth) and find out what pleases the Lord. Have nothing to do with the fruitless deeds of darkness, but rather expose them. For it is shameful even to mention what the disobedient do in secret. . .
"Be very careful, then, how you live—not as unwise but as wise, making the most of every opportunity, because the days are evil. Therefore do not be foolish, but understand what the Lord's will is."
Ephesians 5: 1,2,8-12,15-17