what i am going to say is my own PERSONAL opinion, how I see it. I don't judge other peoples tattoos or people with tattoos so before anyone repsonds and want to bite of my head read this : It is YOUR life and YOUR body and YOUR right to make with it as YOU please. I dont judge YOU and YOUR choices.
Ok, so here is my approach or opinion :
I don't like tattoos, I don't see the worth of them. If you need to ink something under your skin so that you can pettifully remind yourself of some "achievement" to give you strength then you clearly have very low self esteem. You know in your heart what you have done and how, why do you need to "imprint" it on yourself ? You need to show the world what you have done ? Why ?
The other thing is what if you change your mind one day ? Tattoos can be removed but with effort and at great cost, so for most people, once its there its there. Would you want your kids to have tattoos one day when you are 40 but have learnt it sucks, they deteriorate and become "fuzzy" ?
And the last two points of course is what and where on your body. 95% of businesses look at tattoos that are visible with normal work wear is unacceptable.
But if you feel the need to brand yourself with something that means a lot to you and its tasteful, will not affect your work one day and it really really really really really makes you feel better... then its your body and your choice.
And if you are christian (a real one) then you cant...or rather, you shouldnt... as a christian you arent allowed to put ink under you skin. I dont know wjhat other faiths ave to say about it.
good luck and i can see by the way you have asked the question you clearly are a level headed person that thinks things through properly...good approach, keep it that way !
U