In speaking of the sinner “whose portion is in this life” (Psalm 17:14), John Owen says this:
“This is their consolation: a crackling of thorns under the pot, a sudden flash and blaze, that begins but to perish.So that both adversity and prosperity slayeth them; and whether they are laughing or weeping, they are still dying.”
Apart from the Spirit of God abiding within a man, he can have no valid or genuine assurance of salvation. He can heap up arguments of why God should pardon his sin at the last day, but these are the arguments of fools. A sinner can be confident of his arrival in heaven upon death or confident there is no life after death, but all such thoughts are empty and void of truth. Consider how many throughout the ages have comforted themselves to no profit at all saying, “Peace, peace!”, when there was no peace. If your portion is in this life and your joy in the things of this world, then be rightly assured that you have no hope of heaven and no possession of Christ.