The greatest and most blessed work in this world is to proclaim the message of eternal life.
Looking for that blessed hope, and the glorious appearing of the great God and our Saviour Jesus Christ;
Who gave himself for us, that he might redeem us from all iniquity,
and purify unto himself a peculiar people, zealous of good works. (Titus 2:13–14)

In hope of eternal life, which God, that cannot lie,
promised before the world began;
But hath in due times manifested his word through preaching,
which is committed unto me according to the commandment of God our Saviour. (Titus 1:2–3)

But ye shall receive power, after that the Holy Ghost is come upon you:
and ye shall be witnesses unto me both in Jerusalem, and in all Judaea,
and in Samaria, and unto the uttermost part of the earth. (Acts 1:8)

The greatest good we can do while living in this world is to proclaim the message of eternal life.
Everything else will eventually pass away like the wind.

God delivered us from death through the death and resurrection of Jesus Christ so
that we might devote ourselves to this good work.

Jesus Christ, the Almighty Creator, Jehovah God, became flesh and rose from the dead.
Everyone who believes this truth in his or her heart becomes a witness of Jesus.  Hallelujah!