Answer:
Most take the following verse to reinforce the need for being part of a church…of course there are countries and places where meeting in homes, etc take the place of officially joining a church. In scripture when it mentions “church” it actually refers to the Christian community, not a specific building or congregation.
Hebrews 10:25 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.
It did appear common practice throughout both the Old and New Testaments for people to gather together and worship and learn just as our modern day churches do (or at least are supposed to). It doesn’t specifically say you need to be a member as we refer to it today, but membership can show a strong support to the local body and in most cases is probably the right thing to do – although I would not condemn anyone who felt strongly they could not make this step.
The 10% comes from the word “tithe” meaning one-tenth.
Malachi 3:8-10 Will a man rob God? Yet ye have robbed me. But ye say, Wherein have we robbed thee? In tithes and offerings. Ye are cursed with a curse: for ye have robbed me, even this whole nation. Bring ye all the tithes into the storehouse, that there may be meat in mine house, and prove me now herewith, saith the LORD of hosts, if I will not open you the windows of heaven, and pour you out a blessing, that there shall not be room enough to receive it.
I always tell people tithing is a good deal because in the New Testament many didn’t just give 10%, they gave 100%!!
Acts 4:33-35 And with great power gave the apostles witness of the resurrection of the Lord Jesus: and great grace was upon them all. Neither was there any among them that lacked: for as many as were possessors of lands or houses sold them, and brought the prices of the things that were sold, And laid them down at the apostles’ feet: and distribution was made unto every man according as he had need.
Good questions, I hope this helped,
Pastor Brad