We should always examine ourselves to be sure we are in the faith.  We also are to know false prophets and teachers by the fruit they bear.  Some are sowing good seeds and some are sowing bad seeds.  There are various different gospels being preached in Christian churches today but we are told in scripture to be one body, with one mind, the mind of Christ.  How can there be so many strikingly different Christian doctrines?  Well, though there have been many interpretations of Scripture, there is only one true Christian doctrine and only one true God.  Every believer in life is progressing to a state of holy perfection.  This is not about being perfect in everything we do, but is about our life being a constant progression in that direction.  We will stumble and we will fail even though we do not have to and we are no longer under the power of sin nor the curse of the law, but we should never sin willingly, using grace as an excuse to live in sin.  If and when we fail, let us learn from it spiritually to avoid it in the future.  Let our weaknesses be growing pains to us and not just groping in darkness.