Forgiveness increases ones love to God because

1. All of us have sinned in either words, deeds or even in our thoughts and these have made us to distance ourself from God but once we submited to God our sins then we are cleansed and relationship with God is improved. For the Bible Tells us "For God so loved the world that He gave His Own begoten son that whoever believes in Him shall have eternal life". Since Jesus came to save us from our sins and He is love himself and he is one with God therefore once you accept that you have sinned and ask for repentence then you have received Christ with Him then your love for God increases as God is Love.

2. Once you repent and receive Christ as your saviour and believes in Him and then you have also received God Himself and therefore more effort will be put to prayers and thirst for the word of God hence more Love for Him.