Unconditional Love / Conditional Love

We know God's love / forgiveness to be unconditional explained by Romans 6:23. Unconditional love means love with NO limit within forgiveness. 

If anyone hurt you but you forgave him/her, it means you are loving that person unconditionally. Conditional means limited. If you do not forgive whoever did wrong thing to you, it means you are not loving that person unconditionally. God loved you so much so He sent his son Jesus Christ to earth to pay our sin debt when he died on the cross to have all of our sins forgiven so we would never have to face penalty by going to hell as John 3:16 explained.

"For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life." 
(John 3:16)

"For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord." (Romans 6:23)

However if you ever happen to read Matthew 6:15, you might be having difficult time understanding God's unconditional love.

"But if ye forgive not men their trespasses, neither will your Father forgive your trespasses." (Matthew 6:15)

This causes difficulty in my understanding on Romans 6:23 too. I would say this doesn't verify the fact God's forgiveness is unconditional... but that was until when I read Psalm 66:18:

"If I regard iniquity in my heart, the Lord will not hear me" (Psalm 66:18)

I understood so much better. (iniquity = sin) Psalm 66:18 explains that if there is specific sin you hid in your heart and you haven't confessed that to the Lord yet or disagree that specific sin you committed is SIN, that means you are calling God a liar when His Word says:

"For all have sinned, and come short of the glory of God;" (Romans 3:23)

Because unforgiveness is SIN. If you refuse to forgive, that means you are not agreeing that unforgiveness is sin. When you refuse to forgive after a long period of time WITHOUT reconciling (problems solved / forgiven) with a wrongdoer, your heart eventually becomes harden in a process, and that possibly prevents God from hearing your prayer when you attempt to reach out to Him as Psalm 66:18 explained. He cannot hear you when your heart is blocked by sin which you refuse to confess.

"If we say that we have not sinned, we make him a liar, and his word is not in us." (1 John 1:10)

In order to accept the salvation of Jesus Christ as God's personal gift, you must admit that you are sinner in need of a Savior. (Romans 6:23) When you become saved, you will begin to have the fruit of Spirit. Forgiveness is one of the most important virtues that demonstrate the fruit of Spirit in your heart. Refusing to forgive will only hinder your prayers with God. So you are required to make efforts to be like Jesus by being forgiving.