The key phrase there is ‘assembly of the Lord’ ~ does not equate to heaven in my study Bible rather worship services or an exulted office/position back in Moses day.
You can simply pray the prayer of salvation (see Romans 10:8-10) or you can continue to act as experts trying to trip up true believers but you can’t have it both ways. Choose ye this day who you will serve.
Deut 30:12-14 is the basis of the Jewish belief in works based salvation. Romans 10-8 is Paul's alteration of the Deuteronomy 30:14 to promote his agenda, even though the Bible prohibits adding words to the scripture. This is nicely illustrated in this article by Rabbi Tovia Singer
Employing unparalleled literary manipulation, however, Paul manages to conceal this vexing theological problem with a swipe of his well-worn eraser. In fact, Paul's innovative approach to biblical tampering was so remarkable that it would set the standard of scriptural revisionism for future New Testament authors.
A classic example of this biblical revisionism can be found in Romans 10:8 where Paul announces to his readers that he is quoting directly from scripture as he records the words of Deuteronomy 30:14. Yet as he approaches the last portion of this verse, he carefully stops short of the Torah's vital conclusion and expunges the remaining segment of this crucial verse. In Romans 10:8 Paul writes,But what does it say? "The word is near you, in your mouth and in your heart" (that is, the word of faith which we preach).
Predictably, the last words of Deuteronomy 30:14, "that you may do it," were meticulously deleted by Paul. Bear in mind that he had good reason for removing this clause -- the powerful message contained in these closing words rendered all that Paul was preaching as heresy.
This stunning misquote in Romans stands out as a remarkable illustration of Paul's ability to shape scriptures in order to create the illusion that his theological message conformed to the principles of the Torah. By removing the final segment of this verse, Paul succeeded in convincing his largely gentile readers that his Christian teachings were supported by the principles of the Hebrew Bible.
Deuteronomy 30:14
Romans 10:8
But the word is very near to you, in your mouth and in your heart, that you may do it.
But what does it say? "The word is near you, in your mouth and in your heart" (that is, the word of faith which we preach).
The question that immediately comes to mind is: How can Paul deliberately remove a vital clause from Moses' message and still expect to gain a following among the Jewish people? While considering this question, we can begin to understand why Paul attained great success among his gentile audiences and utterly failed among the Jews who were unimpressed with his contrived message.
It is for this reason that although both Paul and Matthew quoted extensively from the Jewish scriptures, they achieved a very different result. Paul was largely a minister to gentile audiences who were ignorant of the Jewish Bible (the only Bible in existence at the time). As a result, they did not possess the skills necessary to discern between genuine Judaism and Bible tampering. These illiterate masses were, as a result, vulnerable, and eagerly consumed everything that Paul taught them. In fact, throughout the New Testament it was exclusively the Jewish apostates to Christianity who challenged Paul's authority, never the gentile community.
You throw a person out of "worship services" for no possible fault of his or hers, and then expect the same person to attain salvation. What then is the use of the said "worship services" or even the congregation if salvation can be attained outside of it? What use are congregations, or churches, even, in that case?