A law establishing a religion is a law saying: "The Episcopal Church is hereby declared the official religion of the state. The Episcopal Church and all its activities will receive exclusive government funding."
A law "respecting" an establishment of religion would not make the Episcopal Church or the Presbyterian Church the official state religion, i.e. establish it - but it would offer lesser privileges to it that other religions were not privy to and which would contemplate or respect it as if it were an established religion.
The law we are discussing does not single out any religion for establishment or even for such lesser privileges and advantages falling short of establishment.
By the way, funds confiscated from taxpayers' income are inherently non-charitable as they are coerced.
Fair enough. They are used for relief purposes, then.
Redistribution to establishments of religion inherently does this by taking earnings from people of one faith and giving it to other religious organizations.
The founders were wise to prohibit Congress from making such laws.