Christians do not lose heart in the face of hardships. In light of eternity, they are but light and momentary troubles in comparison to the far more exceeding and eternal weight of glory in the life to come.
While Moses was receiving the 10 commandments from God, the Israelites quickly fell away into idolatry by forcing Aaron to craft a golden calf. In doing so, they broke the first three commandments by worshipping this golden calf instead of God.
Paul admonished that believers in Christ are like cracked jars, yet they contain an invaluable treasure: Jesus Himself. Believers may experience trials for bearing witness to the Gospel, yet the Father will hold them up for His own glory.