The punishment for sin is not pain in this life. The punishment for each and every sin is eternal death.
Ezekiel 18:4 Behold, all souls are Mine; The soul of the father As well as the soul of the son is Mine; The soul who sins shall die.
Romans 6:23 For the wages of sin is death…
We sin when we give in to our own evil desires and disobey God’s commandments.
James 1:15 Then, when desire has conceived, it gives birth to sin; and sin, when it is full-grown, brings forth death.
Suffering in this life is due to our mortality and has no bearing on our sin.
Ecclesiastes 9:2 All things come alike to all: One event happens to the righteous and the wicked; To the good, the clean, and the unclean; To him who sacrifices and him who does not sacrifice. As is the good, so is the sinner; He who takes an oath as he who fears an oath.
We cannot expiate our sin by suffering in this life. Sin can only be forgiven as a free gift from God through our association with the sacrifice of Jesus Christ. To be forgiven, we must believe and obey the gospel preached by Jesus Christ and his apostles.
Romans 6:23… the gift of God is eternal life in Christ Jesus our Lord.
1 Corinthians 14:1 Moreover, brethren, I declare to you the gospel which I preached to you, which also you received and in which you stand, 2 by which also you are saved, if you hold fast that word which I preached to you…
What God requires of us can be summed up as follows:
After baptism, we cannot live a sinless life, but providing we are making a determined effort to live by his commandments our sins will be forgiven by confession in prayer.
1 John 1:7 But if we walk in the light as He is in the light, we have fellowship with one another, and the blood of Jesus Christ His Son cleanses us from all sin. 8 If we say that we have no sin, we deceive ourselves, and the truth is not in us. 9 If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.
If we do this, we are promised forgiveness of sin, resurrection from the dead, equality with the angels (who cannot sin) and eternal life in the kingdom of God which will be established forever upon the earth at Christ’s return.
May I suggest that you read Your Share in God’s Promises (please click on the title)
I hope you find this helpful.