The Sunday offering is fairly vulnerable to theft or embezzlement unless good checks and balances are in place.
Your congregation should develop policies and procedures that make sure no one has access to the money without another person present, and that there is a paper trail to provide that money can’t go missing on its way to the bank. For example:
After the offering is taken, the offering baskets should be in plain sight on the chancel, or secured in a locked room or safe.
Immediately after the service, the offering should be counted by two unrelated persons working together in the same room.
Rotate the counters so that the same two people are not repeatedly working together.
The amounts received both in checks and cash should be noted on duplicate forms, both initialed by the two counters. One form stays with the offering and the other is given to the treasurer, bookkeeper or other person who reconciles transactions
The funds should be in the custody of two people until they stored in a secure place until deposited. A safe is best. Deposit bags with key locks are available from many banks, along with a key to the night deposit box used by commercial customers.
The collection must not leave the building until it is taken to the bank to be deposited.
Ideally, the person who makes out the bank deposit is a third person, not one of the cash counters.
The deposit slip and counting form (often stapled together) are given to the treasurer, bookkeeper or other person who reconciles transactions, so it can be compared with the duplicate counting form and the deposits noted on the monthly bank statement.