Overall meaning : The life of this world is no more than play and vain amusement, so do not let it make you lose heart and be too weak to engage in jihad. If you truly believe and are mindful of Allah by observing what He commands and eschewing what He forbids, He will reward you in full for your faith. He does not ask you to give up all your wealth. If He were to ask you for all your wealth and press you to spend it all for His cause, you would become niggardly, and He would thus bring your malice to light!
Here you are now being called upon to spend your wealth in order to fight Allah’s enemies and support His religion. Some among you are tight-fisted with their wealth, yet whoever is tight-fisted with his wealth only deprives himself of abundant good and a great reward. Allah is All-Sufficient and does not need you, while you stand in need of Him. If you, people, turn away from obeying Allah, He will replace you with another people who will not be like you in turning away from His religion and being tight-fisted with their wealth. Rather, they will be more obedient to Him than you!