Thanks for the question and sharing your situation.
Let me first say, I totally understand where you are coming from, seeing my mother, who was an uncatechized Christian, had the same sediments when I mentioned I thought about the priesthood. Note: Six months before she passed, she recollected how, when growing up, her father had read Watchtower magazines, so she never had any good Catholic foundation, especially since back then, she became a Catholic to marry my father, a requirement that has been changed by the Church.
Jesus tells us in Matthew 10:37-39:
37 He who loves father or mother more than Me is not worthy of Me. And he who loves son or daughter more than Me is not worthy of Me. 38 And he who does not take his cross and follow after Me is not worthy of Me. 39 He who finds his life will lose it, and he who loses his life for My sake will find it.
yet St. Paul tells us to honor our fathers and mothers (Ephesians 6:2)
- How do we reconcile these two passages?
You didn't say how old you were but if you are living under your parents roof, you have to follow their rules, even though she should not be blocking you from going to prayer meetings. After 18, they have to respect even if they may not like it, your decision to do what you want with your life. They have raised you to be the Christian man you are by age 18.
That said, you should not hide this from your mother because it is who you, Michael, are, and what you want to be.
If the Lord is calling you to the priesthood, you can't ignore that and for this reason I am glad you are meeting with vocations directors to aid in the discernment process. They will be able to explain all the issues involved. As you discern, remember, ultimately, the Church decides, guided by the Holy Spirit. If things don't turn out, a vocation like a Catholic Apologist may be something to look into. The Church always needs more defenders for the Lord's Catholic Church.
The issues you are dealing with have nothing to do with mortal or grave sin.
For sin to be mortal it has to meet all three criteria:
- it must be grave matter
- there must be sufficient knowledge, and
- it must be done with full consent of the will.
If just one of these conditions is missing, it is not a mortal sin.
Nevertheless, lying is always a sin and should be mentioned in Confession.
I hope this helps,