However, what if a Christian truly believes in Jesus and gives Him his life, but later commits a big sin? Like adultery, grand theft, murder, or rape...Is that Christian immediately forgiven without doing anything? Without repenting?
The Apostle John gave instructions to Christians of all levels of maturity in the faith (and he even included himself in the mix this time ... please see the pronouns below, in bold), about what we, as believers, need to do to be forgiven of our ongoing sins.
1 John 1 (NASB 95')
9 If we confess our sins, He is faithful and righteous to forgive us our sins, and to cleanse us of all unrighteousness.
Of course, forgiveness, in this case, is concerned with the "condition" of our already established and ongoing relationship with our heavenly Father,
NOT with our salvation/or "position" in Christ, which is neither changed nor lost when we sin (anymore than children are booted out of their human families when they fail to do what their parents ask them to do).
Also, as King David said to God (after having committed the sins of both adultery and murder), "
Return unto me the ~joy~ of Thy salvation" (He did not ask to be saved again because he knew that his salvation was not lost, even though his sins were heinous, rather, he wanted the ~closeness~ of His relationship with God to be restored to what it once was, because ~that~ was what he lost when he sinned).
Psalm 51 (ASV)
10 Create in me a clean heart, O God;
And renew a right spirit within me.
11 Cast me not away from Thy presence;
And take not Thy Holy Spirit from me.
12 Restore unto me the ~joy~ of Thy salvation;
And uphold me with a willing spirit.
If that Christian does not need to work, then why be good?
To honor and glorify the One who so clearly loved & loves us, first and foremost by choosing to come here and die on the Cross in our stead to save us. I also choose to "be good" for the simple reason that I love Him too, and because I know that honoring, glorifying and obeying Him is pleasing to Him, and that's all I've wanted to do since the day that He saved me (I don't do it to curry favor with Him or anything like that, and I wouldn't do so, even it that was possible .. which it is not).
I believe that our value to God rests in who we are to Him (His true sons and daughters by adoption),
NOT because of what we do (or fail to do) for Him. As the hymn
* says, "
Thou my great Father and I, Thy true son", and that is the relationship that we have with Him, Father and child.
~
Be Thou my vision, O Lord of my heart*
Quite frankly, the works that He has us do are all for our sake (and for the sake of others), because God doesn't "need" anything from us.
Is morality pointless? Does God send sinful people to Heavens because He died for them and so forgave them anyway? So Christians murderers will go to Heavens?
We are ALL sinners, Arkange, Christians too. The only difference is that we (Christians) are also saved by God's grace (by His unmerited favor towards us, IOW). Of course, His grace is hardly unmerited, it's simply unmerited, by us!
Does that Christian need to work to repent? Do penance? Be purified? Go through Purgatory?
What "work" can a Christian do to save himself

According to the Bible, the only "penance" that can satisfy the price that God requires for our redemption and the forgiveness of our sins is the death & shed blood of Jesus Christ, the Lamb of God .. e.g.
Hebrews 9:22. Even our own death is not enough to pay the required price to God, which is why He alone is capable of being our Savior, and it's also why the Bible tells us that the Lake of Fire is eternal.
How do you explain that some Christians really have faith in Jesus-Christ, but they still commit big sins?
We are sinners
saved by grace who are made
God's workmanship as
new creatures in Christ (with a new nature and a new set of desires that are given to us by Him). This means that when we sinned before we were saved, we did so in accord with our old nature. It also means that whenever we sin now, we do so in opposition to our new nature, which is why sinning (which used to be fun for us before we were saved) seems so horrible to us now.
The problem is, our old nature, while subdued and secondary to our new nature, remains with us until the day that we die, so we will always be faced with the possibility of a battle going on between our two natures, and sometimes the old nature wins the day, unfortunately
God bless you!!
--Papa Smurf
p.s. - I have several questions that I've been meaning to ask you, but those will have to wait. Also (in closing), here is one of my favorite Christian quotes for you to consider, by pastor and theologian, Charles Spurgeon. If you have the chance, please let me know what you think of it. Thanks
