One of the more egregious things a teacher of the Bible can do is speak on behalf of God when God has not revealed anything. This idea that God will preserve someone's life until they can be baptized is heretical and presumptive. God has revealed that we are not guaranteed our next minute. That is why obedience to His Word immediately is of the utmost importance. Further, if one does die before one obeys, God cannot, according to His Word, arbitrarily save him based on the condition of the heart at the time of death. To teach this undermines not only the necessity of baptism but the gospel as a whole.  Take a listen to this episode of Cogitations that deals with just such an argument.