When ever one verse is used to prove something always look to either several verses back or several verses forward. In the case of Hebrews 10:25 the verses before verse 25 the words " let us " is written three times, so the writer of Hebrews is speaking to a group of people. So when we get to verse 25 we should all the more reason " Not forsaking the assembling of ourselves together " I don't know about you but it's such a difference being around people that are lost compared to being with other believers in Christ. So if we desire to be uplifted and exhorted, then why do we forsake the assembly of ourselves?