To inoculate means to protect against, theoretically forevermore. There are many ways to inoculate others against Christianity, all but insuring they will never seek the Lord. Stupid Christians are the worst offenders here, doing countless unbelievers and the church a grave disservice. Here are some of the ways in which believers stupidly work to condemn others.

• Many stupid Christians try to sell Christianity as merely a lifestyle of good deeds, staying out of moral trouble, that sort of thing. For those who deem themselves good people--and who wouldn't?--Christianity adds no real value, then. Having defined the faith so poorly, such stupid Christians have all but insured "good" people will not come into faithful obedience.
• Related to the above is downplaying damnation and hell. It's a fact: those not submitting to the Lordship of Christ are condemned to an eternity of torment. We all deserve this and have it coming--were it not for Jesus' salvation. Diminishing the significance of sin reduces the contrast between unbeliever and believer, and it diminishes the value of the faith.
• Failure to provide reasonable answers to tough questions is almost sure to turn people off of Christianity. If you cannot address common questions and objections with logic, reason, and evidence, just keep your mouth shut.
• Hypocrisy. Need I say more? (I will anyway, of course.) Saying one thing and doing another--a sure way to sour the faith for anyone. Your real values are not those you espouse but those you actually live. If you don't consistently exhibit Biblical values, you're a liability to the faith.
• Incorrect definitions of good and evil lead many to believe erroneously that God does evil and people are good. Good means obedience to God or remaining true to His unchanging character (how can God be otherwise?). Evil means disobedience to God (which God can never do).
• Denying the Bible or even portions of it (e.g., science, history, creation, sexuality, etc.), can be lethal to its credibility. If the holiest of Scriptures (to a Christian) are routinely amended, portions ignored, updated for modern times, or creatively reinterpreted as we desire, then our "faith" is merely created to serve our desires. If some of the Bible's truthfulness is denied, the faith may be seen as devoid of any truth at all.

If you see yourself in these, perhaps it's time to take stock of what kind of Christianity it is you practice, because it's not Biblical.