Most religions do teach that a person should not lie or steal, and so forth. But is that sufficient? Would you be happy to drink a glass of poisoned water because someone assured you that most of what you were getting was water?
2 Cor. 11:14, 15: “Satan himself keeps transforming himself into an angel of light. It is therefore nothing great if his ministers also keep transforming themselves into ministers of righteousness.” (Here we are cautioned that not everything that originates with Satan may appear hideous. One of his chief methods of deceiving mankind has been false religion of all kinds, to some of which he gives a righteous appearance.)
2 Tim. 3:2, 5: “Men will be . . . having a form of godly devotion but proving false to its power; and from these turn away.” (Regardless of their outward professions of love for God, if those with whom you worship do not sincerely apply his Word in their own lives, the Bible urges you to break off such association.)