This means that if we have sincerely come to Jesus, accepted that he died for us, asked his forgiveness, submitted to him as our Saviour and Lord, and then do not believe that he has accepted us as one of his family, we are casting doubt on his promise. John puts it more bluntly. We are making God a liar. We must learn to trust his word. We need something solid outside ourselves in which to put our trust.
Feelings come and feelings go, And feelings are deceiving.
My warrant is the Word of God, None else is worth believing. Though all my heart should feel condemned, For want of one sweet token, There is One greater than my heart, Whose word cannot be broken. When he was suffering, at times he found himself greatly disturbed by doubts and uncertainty. Sometime later his wife came into the room and found him leaning over the side of the bed, holding the open Bible underneath it. It is Christ's death that makes the believing sinner safe, but it is God's word that makes the trusting Christian sure.