What Is The World's Strongest Currency?

The answer is: Trust.

This marketing gem by United Overseas Bank Limited made my day as it illustrated and illuminated the strength undergirding currencies in a highly relatable fashion.  

To digress: What Is The Currency of Heaven?

The answer is: Faith.

"But without faith it is impossible to please Him, for he who comes to God must believe that He is, and that He is a rewarder of those who diligently seek Him." Hebrews 11:6 (NKJV)

God's rewards for those who believe in Him are as written in the Holy Bible such as the following from the New King James version (NKJV):

"If any of you lacks wisdom, let him ask of God, who gives to all liberally and without reproach, and it will be given to him." James 1:5

"The blessing of the Lord makes one rich, And He adds no sorrow with it." Proverbs 10:22

"For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life." John 3:16

For more Bible verses, please explore https://www.biblegateway.com