What did John the Baptist do to become a saint?

What did John the Baptist do to become a saint? 

John the Baptist was set aside and filled with the Holy Spirit, even from his mother’s womb (Luke 1:15). He spent his whole life leading others to Christ; his whole existence revolved around preparing the way for Christ. Finally, he was killed by Herod for witnessing to the truth. This is why he is held in such high esteem in the Church. In most artwork depicting the communion of the saints in the Kingdom of God, Our Lady sits on Christ’s right, and John on his left.