All of us can attain to Christian virtue and holiness, no matter in what condition of life we live and no matter what our life work may be. - St. Francis de SalesSt. Francis de Sales wrote the Introduction to the Devout Life in 1609 as the first work dedicated to assisting laypeople as well as clerics in their pursuit of sanctity. It's based on a series of notes he made to his cousin as she prepared for her marriage and letters to others who sought him as a spiritual director amidst the troubles and tribulations of the spiritual life. I am working my way through it right now, and while a bit outdated (for instance, one needs a supplement on receiving Communion daily or very near so that reflects the Church's encouragement of this practice) it nevertheless remains an outstanding aid in the development of one's interior life. You don't realize how much leisure time you have until you read something like the Devout Life, and he advises solid chunks of prayer (St. Josemaria Escriva's way is just as intense).
Our primary vocation is to love, and the callings to the priesthood, religious life, and marriage are stepping stones in which we by the grace of God are made righteous, for by the stain of original sin we are displeasing in the sight of the Lord. By the law, we have come to know sin, but cannot keep the law, something possible only by sanctifying grace, which poured out upon the world from the pierced side of Our Lord, the Beloved Son with whom the Father is well-pleased.
On the other hand, our vocations are not merely stepping stones to eternity in communion with God, and they are ends in and of themselves. God could have made us with the beatific vision, so we would be with Him from the moment of creation through eternity. There would be no fallen Man, no sin. But Love then would not be an act of the will as it is understood now, and we would lose the radical and beautiful ability to love one another-in particular our families- so that we all might come to holiness, and not loving them in virtue of their communion with God in Heaven. There would be no salvation history, I would think, no happy fault to bring us the great Redeemer.
In love, there is no method, there is no one-size-fits-all. As far as the measure goes, it is loving without measure to paraphrase St. Bernard. And it's hard, for we are called to die to ourselves to give to others, to the point of giving our lives for our friends. It's hard, because we want to love, but we are caught in sin. But the Lord is always with us, carrying the yoke with us, making our burdens light and sweet.
This is not a new idea of the modern Christian era. It is clear from Scripture, the Gospel and its account of Apostolic times, that Christ came to make all righteous, but sometimes that was obscured by the heavy emphasis (a true one, lest we forget) on the monastic and especially priestly life, dedicated completely to the contemplation of the Lord. St. Josemaria Escriva and then the teaching of Vatican II called for an end to the denigration of marriage (notice that equality is not called for, and the monastic vocation must permeate the home in a way), recognizing that sanctity is expected for all, that it is possible for all, and that the Church in her apostolic work needs to provide for the married and other laypeople.