Immediately they followed Him

Matthew 4:17-22
Jesus said, “and I will send you out to fish for people.” At once Peter and his brother Andrew left their nets and followed him.
Jesus called James and his brother John, and immediately they left the boat and their father and followed him.
Here he calls his first disciples and begins his public ministry.
Why?
They heard the calling of Jesus they followed Jesus immediately.
Send you out to fish for people : For people is more important than fish. Spirit is more important then living.
Follow Jesus should be whole heart and whole mind and strength. Discard anything or any concerning. God will purport us.
How?
Reply to God's calling at once, but we need to identify does it is really calling from the Lord?