Only Saints Go to Heaven

From St. Lous de Montfort's True Devotion: Consecration to Mary:

There are those who think that it is sufficient to be saved and that it is not necessary to be a saint. It is clearly not necessary to be a saint who performs miracles and whose sanctity is officially recognized by the Church. To be saved, we must take the way of salvation, which is identical to that of sanctity. There will be only saints in heaven, whether they enter there immediately after death or after purification in purgatory. No one enters heaven unless he has that sanctity which consists in perfect purity of soul. Every sin, though it should be venial, must be effaced, and the punishment due to sin must be borne or remitted, in order that a soul may enjoy forever the vision of God, see Him as He sees Himself, and love Him as He loves Himself. Should a soul enter heaven before the total remission of its sins, it could not remain there and would cast itself into purgatory to be purified.