As a former (retired) worship bassist of many years for a couple of big mega-churches, I can tell you that the best thing you can do is to get a setup for in-ears that allows you to get the sound YOU want in your own ears and not worry about the sound the congregation is hearing. You have no control over the FOH sound people and how they mix on any given Sunday. Let that go right away and concentrate on getting the sound you want for yourself.
If you are still using an amp onstage, you should find a way to split your signal, so that you can hear one thing and the soundman will get your clean signal. You may still find that sound people will just tell you to turn the amp down anyways. That's a fight you won't win either because the congregation always comes first.
If you have an active/passive bass like an Ibanez, never use the active section. It's just going to mess with the soundman if you are constantly changing the EQ of your bass tone. Try to send him/her the cleanest passive bass signal you can. They will do whatever they are going to do to it anyway.
I will echo some of the posts on here - play with a flat EQ through a REALLY good DI box. Sansamp BDDI is great as a preamp but the thing that is between your bass and the FOH sound is your main DI. They will give you something like a Radial DI box, typically. These are okay, and give a decent clean tone, but if you want pure bass tone you might think of getting a tube DI box somewhere down the line (if you can afford one). And just practice, practice, practice. Simple bass lines and quarter notes using a metronome or drum backing track. You aren't going to be playing anything too complex on a worship stage (usually) unless you are in a Gospel rhythm section.
As for mixing your own tone for in-ears you can try something like I use to use... maybe?
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This is my setup from around 2017 - I used two Sansamp BDDIs, and an Ampeg SCR-1. Forget about the rest of the signal chain for now. Here's how the signal chain runs:
Bass into the input of BDDI 1 > output to DI (in my case a REDDI) for FOH signal (this is what the soundman gets). I just set this first Sansamp to flat (knobs at 12 o'clock) and NEVER change it. This is your flat bass signal.
Parallel output from 1st BDDI to 2nd BDDI input. This is how you split your signal. This signal is now independent of the signal going to FOH sound.
Output from 2nd BDDI to input of Ampeg SCR-1.
Ampeg SCR-1 has an Aux input - plug in the signal from whatever monitor system you have (we had individual packs so I just ran a 3.5mm lead from the phone output of the pack) into the Aux in of the Ampeg. Now plug your actual in-ears into the phones out of the Ampeg. Mix to your own liking using ONLY the knobs on the 2nd BDDI and the Ampeg SCR-1. Leave the first BDDI alone.
You may need a few extra cables and an in-ear headphone cable extension for this setup but you will be able to get your own mix and never worry about how you sound out front to the congregation again. Plus you still get the mix from the monitor system as well. One day, when you can afford to, try it out.