What follows are Alan's thoughts about this often quoted passage...
And let us consider how to stir up one another to love and good works, not neglecting to meet together, as is the habit of some, but encouraging one another, and all the more as you see the Day drawing near. (Hebrews 10:24-25 ESV)
What are believers required to do according to this verse?
The command in this passage (actually, an imperatival use of the subjunctive) is "let us consider". The purpose of "considering one another" is to stir up love and good works. Thus, the author of Hebrews expects believers who have the freedom to enter the presence of God (Heb 10:19) and who have Jesus as their high priest (Heb 10:21) to demonstrate that by thinking of ways to exhort others toward love and good works in their lives. This is the command, not "assembling".
So, what part does "assembling" play in this passage? It plays a secondary role. The author of Hebrews recognizes that we cannot exhort one another towards love and good works if we never meet with one another. Similarly, we cannot stir up one another towards love and good works if we do not encourage one another. The two participles ("not forsaking" and "encouraging") play an important, but secondary, role in the requirement of considering one another in order to provoke love and good works in each other's lives.
So what? We're still supposed to assemble together, right? Yes, in fact, according to Scripture, believers will want to meet together with other believers. Assembling together is not required in Scripture, but it is expected. However, attendance alone does not meet any scriptural requirements. It is possible to meet together with other believers and never fulfill the purpose of thinking about how to spur one another on towards love and good works, and then exhorting them towards that goal. A "perfect attendance" award means nothing to a believer.
If we meet together in a way that precludes us from encouraging one another toward love and good works, then we are not meeting in a way that Scripture prescribes or describes. Similarly, if we require attendance, but do not allow believers opportunities to exhort one another toward maturity, then we are not helping people to follow the teachings of Scripture.
Instead of someone saying, "I don't think I've seen you around here in the last few weeks", what if they said, "I noticed that you haven't encouraged anyone around here in the last few weeks".
Yes, I know. It is much easier to count noses. It makes us feel better to have a "full house". But, attendance means nothing if people are not exhorting one another toward maturity in Christ.
Yes, I know. In our mega-gatherings we cannot possibly know whether or not people are encouraging or being encouraged. But, is the answer to the situation to change the scriptural responsibilities of believers?
Yes, I know. Some will suggest that we have "small groups" in order to encourage one another. The only problem with this answer is that Scripture only gives one reason for believers to gather together, whether there are a large number of people or a small number of people: edification.
So let's continue meeting together - whether in large or small scheduled weekly meetings or in large or small spontaneous meetings. But, let's come together for the right reason: not to count noses and record attendance, but to consider one another in order to stir up one another towards love and good works.