In John 12:27-50, we have Jesus' final appeal to the world before spending his final days focused on his disciples. After explaining the meaning of his death, he also explained why so many did not believe in him. Then he summarized his teaching in his last words to the crowds, giving them one final opportunity to believe in him. (sermon notes)
God fulfills his plan against human opposition and even through human suffering.
Although it is impossible to say what is the best thing about being a Christian, the theme of Galatians 4:1-7 is an excellent candidate...
The construction of the tabernacle foreshadowed greater dwellings of God, which he keeps building by plundering the nations.