Lets look at what God says
Heb 10: 14 for by one offering, he has perfected forever (positional sanctification or as you say, having our sins cleansed) those who are being (ongoing process) sanctified
Sanctification is a long process. Which will end in the final result. Or glorification.
Salvation, or "getting saved" is a long process. Which will end in the final result. Or glorification.
Is that true? If being made holy is a "long process" when Scripture in this rare instance uses a
present tense, what are we to make of faith and belief and the New-Birth which are almost always in the
present tense? Someone is apparently not saved today, it is a long process because God uses the
present tense?
Hebrews 10:14 is not speaking of glorification, but being made holy here and now! The perfect tense tells us that by one offering, God has perfected (perfect tense, indicating a past action with continuing results up to this moment) forever, those who are (present tense) being made holy (now).
In context it is most likely speaking on the very same subject at the beginning of the verse as it does in the latter part. The perfect tense can tell us of the past up through the present, but it cannot extend beyond there. The present tense is a here and now action. The point that the passage is making is not that sanctification or perfection is a long drawn out process, but by that one Offering, what God has done in the past, continues, and He is doing so in the present in those that believe.
Most references in the New Testament concerning a Believer and holiness is in the aorist tense, indication a decisive action, and not a process. The starkest fact is that the New Testament does not know anything of a
future tense holiness or sanctification. Holiness is not ever held out as a future even t in the Believer's life. Hoping in glorification for the completion of holiness is not what Scripture teaches.