While it is not necessary that a doctrine to directly rest upon explicit statements, yet as with the Trinity, it should be soundly derived from clear texts, and for which the doctrine of purgatory fails, but which supports the doctrine that all true believers go to be with the Lord forever upon departing from this life, as will be shown.
The argument here for purgatory is based upon the premise that Jesus commanded souls to be as perfect as God, quoting Mt 5:48 which states, "Be ye therefore perfect, even as your Father which is in heaven is perfect, " (Matthew 5:45) ,” which is in context refers to treating your enemy benevolently. However, this does not teach that the achievement of absolute moral perfection in this life is a perquisite for salvation, and which would require redefining salvation, and is tantamount to placing one under the Law. (Gal. 3:10)
For while salvific faith is one which characteristically effects the “obedience of faith” toward its Object (which faith in any moral authority will do, and which is an overcoming kind of faith, (Rv. 2,3), and grows towards the maturity which is called perfection, (Col. 1:28; 4:12; Ja. 1:4; 3:2; 1Jn. 4:17) and which faith has “great recompense of reward,” (Heb. 10:35), yet Scripture states that believers (being of true faith) are presently saved (Titus 3:5), and positionally perfect (Heb. 10:14) and seated in Heaven. (Eph. 2:6)
Those who lack characteristic practical holiness in the obedience of faith, which (like David) includes repentance when convicted of sin, (1Jn. 1:7-9) but who assent to a different gospel (such as based upon morally earning it: Gal. 5:1-4) or who deny the faith (1Tim. 5:8) by knowingly continuing impenitently in sin, departing from the living God, (Heb. 3:6,12,14; 10:25-39) evidence they have rejected true faith (or never had it) and will be lost if they die in that state, and not go to purgatory.
And in contrast to the Scripture texts that are enlisted in support of the Roman tradition of purgatory which typically either refer to punishment of the lost or chastisement in this life or of loss of rewards when the Lord returns, wherever the NT actually refers to the postmortem existence of believers (which are all called “saints), it places them with the Lord.
The apostle Paul, while he told the Philippians that was he not “already perfect,” (Phil. 3:12) was yet torn by two desires, “to depart, and to be with Christ; which is far better ,or to abide in the flesh to minister to the saints. (Phil. 1:23,24)
Likewise he stated to the Corinthians, "We [plural] are confident, I say, and willing rather to be absent from the body, and to be present with the Lord." (2 Corinthians 5:8)
In addition, the Thessalonians, which were still undergoing growth in grace toward perfection, were assured that if the Lord returned, which they expected in their lifetime, so would they “ever be with the Lord.” (1Thes. 4:17)
And while the Corinthian believers were certainly not fully mature, yet the apostle taught that at the Lord's return then that is when they would be like the Lord, (1Cor. 15:49-57) at which appearance is when believers will fully be made perfect. (1Jn. 3:2)
To which is added the contrite confessing criminal on the cross who went to be with the Lord upon his physical death, (Lk. 23:43; cf. 2Cor. 12:4; Rv. 2:7) as did Stephen. (Acts 7:59)
And we may be certain that the contrite confessing criminal had not yet attained moral perfection, which is one reason given for purgatory, the other being the need to atone for sins which the believer was not sufficiently chastised for in this life in compensating for them, and thus Rome teaches that such must atone for “in the life beyond through fire and torments or purifying' punishments.” (INDULGENTIARUM DOCTRINA; cp. 1. 1967)
However, what Scripture only reveals growth in grace and overcoming as being realized in this world, with its temptations and trials, (1 Peter 1:6-7; 1Jn.2:14; 5:4,5; Rv. 2.7,11,17,26; 3:5,12,21) where alternatives to submitting to God can be made (suffering itself does not make one mature) and thus it was here that the Lord Himself was made “perfect,” (Heb. 2:10) as in being “in all points tempted like as we are, yet without sin.” (Heb. 4:15)
Moreover, while Christians will be judged for the things they did as a believers, (Rm. 14:10-12; 2Cor. 5:10) as in how they built the church, this occurs after the Lord's return, (1Cor. 4:5; 2Tim. 4:1,8; Rev.11:18; Mt. 25:21-23; 1Pt. 1:7; 5:4) and is the suffering of the loss of rewards and the Lord's disapproval. (1Cor. 13:8ff) And which is contrary to purgatory, which has souls suffering in ongoing torments upon death in order to atone for sins and become perfect.
See here as regards 1 Cor. 3.
Note however that the “official” Roman doctrine of purgatory is ambiguous enough that it is open to much interpretation, so that it even may be taught, albeit inconsistently, that the suffering is for a moment, or is hardly even suffering.
Finally, the reality is that the doctrine of purgatory does not rest upon or require Scriptural substantiation, only that it does not contradict Scripture according to Rome's interpretation, and instead it is a tradition which rests upon Rome infallible declaration of herself as being infallible, while the Eastern Orthodox reject the purgatory of Rome (among other things) based upon their interpretation of Tradition and Scripture.
But for those who are prone to attempt to justify purgatory by Scripture, though that is not their supreme authority, i have engaged in extensive exchange on this, as here, and which little should need to be added.
It astounds me that people fall for that purgatory tripe. If Jesus perfected us by His suffering and death and that was complete how could anyone deny Christ and state we have to yet be perfected?