We often look for happiness through relationships, money, and material things. These can bring a degree of temporary relief, but happiness is circumstantial and based on what is happening at the moment.
Joy is our true heart's desire and it is eternal, despite our current circumstances; God is the only one that can bring us true joy, then we are able to share it with others.
To seek means to crave, pursue, and go after something sought. The Lord desires for us to live with His joy and to be permanently and consistently satisfied. This comes from spending quality time with Him and studying his word, talking to Him in prayer and sitting quietly in his presence for the answers you seek.
The truth is what we really need to live a joyful life, but you have to come to a place of the acceptance of the truth...the choice is ours to make...(joycemeyer.org)