“The heart is deceitful above all things, and desperately corrupt; who can understand it?” (Jer. 17:9). There is also the possibility of falling from grace through mortal sin, and even of falling away from the faith entirely, for as Jesus told us, there are those who “believe for a while and in time of temptation fall away” (Luke 8:13). It is in light of these warnings and admonitions that we must understand Scripture’s positive statements concerning our knowing and having confidence in our salvation.