@gum_rummy
The WHO is a UN agency that advocates and guides global government health initiatives, it doesn't provide aid.
The International Red Cross and Red Crescent Movement + Magen David Adom also doesn't provide aid, but it's local partners do (Canadian Red Cross, Jordanian Red Crescent, etc). Many of these partners are secular but many others are religiously affiliated, particularly in Africa and the Middle East. The cross, crescent, Magen David terminology should be a giveaway.
But as to my initial point, as a comparison that's easily verifiable for you let's look at UNICEF.
You use it as a example of a large secular aid organization, so let's compare it to one of the smaller religious aid organizations, Samaritan's Purse. Compared to the Catholic Church's charities and various Islamic aid organizations or groups like World Vision, Samaritan's Purse is small beer.
And let's stick to one metric, we'll use UNICEF's Goal 1; maternal and newborn health, immunization, child health, medical treatment and care, HIV prevention, early childhood development and adolescent health and nutrition.
UNICEF also spends a lot of money on promoting rights and lobbying governments, and while these things may be worthwhile, it's debatable whether they constitute charity as commonly defined, so this will be strictly on the UN's Goal 1 criteria.
In the most recent year available for UNICEF, 2018, it spent $352.8 million of it's own resources on Goal 1 aid.
In the most recent year available for Samaritans Purse, 2019, it spent $454.4 million of it's own resources on Goal 1 aid.
Now I'm not posting this to diminish the excellent work that UNICEF is doing, but to demonstrate an example of how even a middling religious charitable organization can measure up against one of the biggest secular organizations.
Citations:
1. https://www.unicef.org/reports/global-annual-results-2018
Download link for the 2018 Global Annual Results Report pdf is a blue button on the right. The financial report expenses are on page 200, as
Survive and Thrive.
2. https://s3.amazonaws.com/static.samaritanspurse.org/pdfs/SPConsolidFin2019-PublicDisclosureCopy.pdf
The expenses are on page 5. I deducted depreciation and administrative fees (postage, Buildings and equipment, etc).