Every single one of us are influenced by others. It doesn't matter how strong our character, our faith, our commitment, we can be led in a bad direction by those we care about. This is why it is so important to be careful of the relationships we cultivate.
Solomon, a paragon of wisdom, was influenced by his wives. "But King Solomon loved many foreign women, as well as the daughter of Pharaoh; women of the Moabites, Ammonites, Edomites, Sidonians, and Hittites-from the nations of whom the Lord said to the children of Israel, 'You shall not intermarry with them, nor they with you. Surely they will turn away your hearts after their gods.' Solomon clung to these in love." (1 Kings 11:1-2). In verse 4 of the text, "For it was so, when Solomon was old, that his wives turned his heart after other gods; and his heart was not loyal to the Lord his God, as was the heart of his father David."
There are a multitude of examples of such evil influences that can be seen throughout the Old and New Testaments. The pattern is repeated again and again in our own lives. Paul knew this truth, and warned, "Do not be deceived: 'Evil company corrupts good habits.' Awake to righteousness and do not sin; for some do not have the knowledge of God. I speak this to your shame" (1 Corinthians 15:33-34).
Seek out the companionship of other Christian friends, family and spouses. Avoid evil companions. Our souls may very well depend on it!