The words service and ministry are nearly synonymous. A slight difference between the terms can be found in motivation. Whereas service is sometimes used to describe any form of paid or unpaid work done for the benefit of others, ministry paid or unpaid always involves work done unto the Lord (1 Cor. 9:12) and may also benefit others. That is why Jesus said that even a cold drink of water given “in the name of disciple” would not lose thier reward (Matt. 10:42).
An essential truth about the theology of ministry is that one’s motivation in doing it is crucial to how God views an act of ministry. Works done for the wrong motives are rooted in pride and self-indulgent purposes or rewards (Gal. 5:13). Ministry, on the other hand, is always motivated by/for the glory of God and for the good of others (Eph. 2:10). In this way, any act of altruism becomes sacred when done for the cause of Christ.