You may find this hard to believe, but I agree with most of what you said, which I emboldened.
At that same time, if I understand you correctly, you are saying that if one refuses to forgive, then He never was a child of God, and therefore never had salvation. I'm guessing this goes against your denomination's doctrine.
I am not inclined to believe such a thing. I believe one can lose their salvation, after they have obtained it.
I also believe one does not have to repent of their dead or evil works in order for them to receive salvation by faith in Jesus.
I'm not trying to be mean here, but you said, 'And since faith is the only basis of all salvation', then that leaves unforgiveness or holding a grudge against someone, out of the equation, doesn't it?
Aren't we forgiven of every sin when we believe and confess Jesus as lord?
I am convinced that we don't need to repent before we are saved, but after.
2Co 4:13 We having the same spirit of faith, according as it is written, I believed, and therefore have I spoken; we also believe, and therefore speak;
Rom 10:8 But what saith it? The word is nigh thee, even in thy mouth, and in thy heart: that is, the word of faith, which we preach;
Rom 10:9 That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.
Rom 10:10 For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.
1Jn 1:9 If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.
I believe, the main purpose of forgiving others, or repenting of all our sins, is that God might forgive us of our sins that we committed after salvation, that the curse of the law of those sins we committed, might be removed from us through the blood of Jesus, thereby restoring us to fellowship with God, so we might, by faith, get healed, delivered, set free from whatever, and/or get our prayers answered, and that we might receive and walk in the blessings of Abraham and in the fullness of the blood covenant that Jesus has made available to us through the work on the cross.
I believe there is a sin that leads not only to physical death, but eternal damnation as well. To be perfectly honest, I don't know what that is, but if it were anything, I would think unforgiveness would be it.
As for faith, if I were to put it in its simplest form, I would say that it is speaking and acting on what you believe. Speaking alone is also acting on that belief, as quoted above.
For example, let's say a person has an illness, and that person prays for God to heal them, then goes and takes some medication or goes to the doctor's office to possibly alleviate the symptoms.
What was the person's faith in? God and His word, or in the doctor and the medication?
A person will speak and act on what they really believe in their heart.
Mat 12:34 O generation of vipers, how can ye, being evil, speak good things? for out of the abundance of the heart the mouth speaketh.
Mat 12:35 A good man out of the good treasure of the heart bringeth forth good things: and an evil man out of the evil treasure bringeth forth evil things.
Forgiveness or the lack thereof, I believe, is an act of the person's will.
Your thoughts ma'am?