Many people claim to be saved already, as if the race was already finished. This is called the Sin of Presumption, and in doing this, a person places himself as the judge of his soul and assumes that power which is reserved for God alone. For Christ is our judge and He alone will call out the sheep from the goats (Matt. 25). For one to presume his own salvation he takes on a certain sense of pride, and this pride has the power to ultimately cause his downfall. He compares himself to the “sinner” and calls himself good. But what is good? St. Paul tells us to rejoice in our weaknesses because only in rejoicing in our mistakes and our faults do we give glory to God. St. Paul also tells us that we must persevere to the end of the race, and that we must train our minds and bodies to do only the will of God, lest after preaching to others we ourselves are disqualified (1 Cor. 9:24-27).
Here is an excerpt from Saint Augustine on the matter. This is from a letter he wrote against the Pelagian Heresy in 390 A.D. In this letter he states that no one is certain and completely secure of his own salvation, until he is received into the Gates of Heaven.
But, moreover, that such things as these are so spoken to saints who will persevere, as if it were reckoned uncertain whether they will persevere, is a reason that they ought not otherwise to hear these things, since it is well for them “not to be high-minded, but to fear.” (Romans 11:20) For who of the multitude of believers can presume, so long as he is living in this mortal state, that he is in the number of the predestinated? Because it is necessary that in this condition that should be kept hidden; since here we have to beware so much of pride, that even so great an apostle was buffeted by a messenger of Satan, lest he should be lifted up. (2 Cor. 12:7) Hence it was said to the apostles, “If ye abide in me;” (John 15:7) and this He said who knew for a certainty that they would abide; and through the prophet, “If ye shall be willing, and will hear me,” (Isaiah 1:19) although He knew in whom He would work to will also. And many similar things are said. For on account of the usefulness of this secrecy, lest, perchance, any one should be lifted up, but that all, even although they are running well, should fear, in that it is not known who may attain,—on account of the usefulness of this secrecy, it must be believed that some of the children of perdition, who have not received the gift of perseverance to the end, begin to live in the faith which worketh by love, and live for some time faithfully and righteously, and afterwards fall away, and are not taken away from this life before this happens to them. If this had happened to none of these, men would have that very wholesome fear, by which the sin of presumption is kept down, only so long as until they should attain to the grace of Christ by which to live piously, and afterwards would for time to come be secure that they would never fall away from Him. And such presumption in this condition of trials is not fitting, where there is so great weakness, that security may engender pride. Finally, this also shall be the case; but it shall be at that time, in men also as it already is in the angels, when there cannot be any pride. Therefore the number of the saints, by God’s grace predestinated to God’s kingdom, with the gift of perseverance to the end bestowed on them, shall be guided thither in its completeness, and there shall be at length without end preserved in its fullest completeness, most blessed, the mercy of their Saviour still cleaving to them, whether in their conversion, in their conflict, or in their crown!
