“Not forsaking the assembling of ourselves together, as the manner of some is; but exhorting one another: and so much the more, as ye see the day approaching.” - Hebrews 10:25
It is the place where the Lord said that He would meet together with His people, even if only two or three where gathered to meet in His name. We do not have this promise sitting at home. Private worship is good, public worship is better.
It is the place where the sheep are fed and led by the Spirit of God and the word of God. This is why God gave pastors and teachers. (Eph. 4:11)
Empty seats equal empty hearts. I assure you there is no one in heaven off to himself praising God, they are assembled together singing, “worthy is the Lamb….”
It is the place where the gospel ordinances, the Lord’s Table, and baptism, are to be administered. Not privately, but publicly.
The most important reason, God said, ‘don’t forsake the assembly…’ to do so is rebellion.
It keeps you from growing cold and indifferent. Take a hot coal out of the fire, and see how long it takes for it to go out. Those who forsake the assembling of God’s people eventually grow cold, and forsake God.
The very manner (custom) of apostasy is forsaking the assembly, “…as the manner of some is…” (Heb. 10:25)
"For a day in thy courts is better than a thousand. I had rather be a doorkeeper in the house of my God, than to dwell in the tents of wickedness." (Psa 84:10)