Whether you trusted Christ as a four year old or a twenty-four year old, in order to be saved you had to realize that you were a sinner headed to hell and that you needed to depend on the gift of Christ dying for you to forgive you of your sins and take you to heaven someday.
If you are a Christian, then you have experienced spiritual grief. If you were four at the time, then your grief was likely different than the one saved at twenty-four. That is okay. As you grow as a Christian you will likely experience this grief numerous times and in different ways.
Just as there is no rhyme or reason to grief over loss, there is no rhyme or reason over the spiritual grief you experience and how you show your grief. Some people cry. Some people go away to be alone to deal with their sin. There is no right way. God only asks that we sorrow over our sin enough to turn from it. That means that we will try not to do it again. We desire to walk towards God and away from that sin.
Now does that mean you won't once again walk the wrong way? Nope
No matter how "good" a Christian you think you may be, you will likely struggle with sin. If you don't think you do, then you are probably struggling with the sin of pride. I John 1:9-10 says it like this, "If we confess our sin, He is faithful and just to forgive us our sin, and to cleanse us from all unrighteousness. If we say that we have not sinned, we make him a liar, and His word is not in us."
Spiritual grief may be a daily thing for you. If you sin, ask God to forgive you. Don't over-think it, just turn from the thing or things you did that is against God's Word, and begin going in the right direction.
We should not take this lightly, but we should also not berate ourselves. God would have us to live joyfully without the weight of sin keeping us from that joy.
Although everyone needs to turn from sin, sometimes there are sins that beset one person more than another. I know from experience that anger and bitterness are sins that can easily take hold in a trial. They can so easily creep in that they can become a way of life rather than a sin in our own mind. I am and have been guilty of this. It is something that convicted me between these lines.
Unlike the grief of loss, this grief can be done with quickly. Because of the grace of God we can confess our sins and have them separated from us and from the mind of God. Don't hold on to sin and cause God to grieve. Grieve over it, put it away, and live in joy.