Hi there,
Thanks for the message and had a few minutes to share through scripture the answers to your questions.
I’ll first address “keep”
Yes, I agree with the definition of “keep” by Strong, I do find it odd you agree with Strong here, but not his translation on Heb 4:9 which means “the keeping of the Sabbath” for God’s people, but I will get back to the subject.
I will show you two usages for keep- which means guard and observe.
The same word in John 14:15 for keep is also the same greek word used in Math 28:20 the Great Commission
Math 28:20 teaching them to observe all things that I have commanded you; and lo, I am with you always, even to the end of the age.” Amen.
Which means to do. We are called to be doers of God’s Word, not hearers James 1:22
A good usage of guard is the New Covenant- God’s law written in our hearts which we should guard, or keep there because this is God giving us His righteousness. As long as we are in Him and not rebelling against what He placed in our hearts His law- we will have His righteousness so it is very important to guard God’s law and let no one change our minds as that is an enmity against God Rom 8:7-8
As far as how we are saved. We are only saved by grace through Jesus and His blood. Everyone deserves the death penalty because all has sinned. Jesus died to take the death in our place and when we are in Him, we receive His righteousness. We have no righteousness of ourselves and as soon as we are no longer in Him, which means a relationship with Him we will not have His righteousness. If we remove even one tittle of jot from God’s law Mat 5:18 that He personally writes in our hearts we have cut that relationship, and I don’t mean the occasionally slip and fall that a righteous man will go to Jesus immediately when stumbling for repentance, cleansing and sanctification. I am referring to not hearing His law and being hostile to it. Rom 8:4-8 Paul makes very clear that is the carnal mind and those who are in flesh (sin) cannot please God. If we are in Christ we have a relationship with Him, He is going to be able to mold our hearts and it will be done based on what He deems righteous Psa 119:172 and what He deems Truth Psa 119: 151 and His Righteousness and Truth is never changing, which is why if we break one commandment in the NC we break them all James 2:10-12. All of God’s commandments are about our relationship with God, but the 4th commandment reveals who gives us that power to have that relationship and its the one commandment that God said to Remember, is holy and blessed by God and yet the one commandment man wants to rebel against for some strange reason. It’s almost like they will do anything but that and its the one commandment that God said Remember perhaps for this very reason.
So while we are only saved by the blood of Jesus through faith alone, not everyone who says Lord Lord will be saved. We all have to make it through Judgement before one is deemed righteous and is saved. If we hold on to Christ’s righteousness and not rebel against what He writes in our hearts we be saved by grace through faith by His works, not our because through His power He can change us from the inside out, we just have to have a willing and moldable heart because our ways are not God’s ways and why we have to depend on Him and His righteousness.