The Bible talks about both good and bad influences.
About bad influences:
The Bible talks about a little yeast working through the whole batch of dough. It asks us not to walk in the counsel of the wicked; not to stand in the way of sinners and not to sit in the seat of mockers.
It talks about the woman Folly who cries out: Stolen water is sweet; food eaten in secret is delicious.” But her guests who are influenced by her end up in the depths of the grave.
Jesus also asked us to remember Lot’s wife. Now Lot had pitched his tent near wicked cities. And its influence might have been so strong on his wife that she looked back and became a pillar of salt.
About good influences:
Talking about positive influences the Bible asks us to open our lives to the influence of God’s Word, and to hide it in one’s heart so as not to sin against God. It asks of us to train a child in the way he should go so that even when he is old he will not depart from it.
Jesus asked us to be the salt of the earth: To give taste, to purify, to act as a preservative, making sacrifices for the good of others and being a positive influence in the environment you live in.
Paul asked us to be blameless and pure, children of God without fault in a crooked and depraved generation. You and your positive influence then will shine like stars in the universe as you hold out the word of life.