1 Corinthians 9:7
What soldier ever served [in the army] and paid his own expenses? Who [ever] planted a grape orchard and did not get to eat some of the grapes it produced? Or, who [ever] tended a flock of goats and did not get to drink some of the milk?
2 Corinthians 10:4
For the weapons of our warfare are not like the world's [i.e., which rely on human ingenuity and unspiritual principles], but they are empowered by God to overthrow [Satanic] fortifications.
1 Timothy 1:18
I give you this instruction, my son Timothy, in keeping with the previously spoken prophecies [i.e., predictions] about you, so that by [following] them you will fight the good battle,
1 Timothy 6:12
Fight the good battle of the faith; take hold of never ending life, to which you were called [i.e., by the Gospel. See II Thess. 2:14], [when] you made the good confession in the presence of many witnesses. [Note: This "confession" probably refers to a person's acknowledgment of Jesus as Lord and Christ prior to his immersion. See Acts 2:36; Rom. 10:9-10].
2 Timothy 2:3-5
[Be willing to] suffer hardship with me like a good soldier of Christ Jesus.