What must grow and change in us while on earth to merit Heaven?
“The hereafter provides no more opportunities for change. So this leaves our life on earth as the only time during which changes possible. St. Paul says, ’Behold, now is the accepted time; behold now is the day of salvation’.” (I Cor. 6:12)
“Let us therefore strive for the mastery in the time of this gift. It is a day of grace, of grace divine, wherefore with ease even we will obtain the crown (of heaven)… so how do we use this ‘accepted time’ to benefit us for all eternity? The Church, in her wisdom, has made available to us the sacraments for this purpose: Baptism, Confession, Communion, and Holy Unction. But none of these can help us in the depths of our being or effect the necessary essential change in us without our own contributing effort and without that crowning virtue: humility. A baptism casually buried in the mire of subsequent sin, upper functionary confession, communion taken without the fear and devout love of God, and holy action received without fervent belief in its power of healing–all these are useless to us. Indeed they are a mockery and sacrilege.
The change must take place in us must be in our heart, ‘ with much groaning and weeping’. (Rom. 8:23) It must be real. For only the real and the cured can enter heaven.”
St. John Chrysostom, pp.775, The Bible and The Holy Fathers