The primary purpose of man on earth is for God's own pleasure. Revelation 4:11 says, Thou art worthy, O Lord,,, for thou has created all things and for thy pleasure they are and were created.  So man is created to serve God's own interest on earth and not God serving our interest. Today man is no longer interested in serving God's interest, that is why nature are working against them, nothing seems to obey man again, because man does not obey God again.

I hear people going to church often say, am going for service, yet they are not serving anything, they do nothing in the church, someone else usher them into the church, clean the chair they sat in the church, someone sing for them and even preach to them. Yet they keep on complaining of one things or the other about the church. They see church as pastor or some members property and that, them coming to church is for pastor own good.

My dear, the church is the body of Christ and is owned by Christ and not pastor or any member, so whatsoever you are doing in the church is unto God not unto man. Exodus 23:25-26 says and you will serve your God, and He will bless your bread and water, take sickness away from you,, none shall cast their young, nor be barren, and I will fulfill your days. You are there lamenting of one affliction, issues or the other, because you refuse to serve God and waiting for God to keep on serving you always.

God will bless your work: God is ever committed to bless us, but He is looking for those whose heart pants after his work to bless. Those who will not consume it on their lost. (James )

God will favour you with divine health: Exodus 23:25 says I will take away sickness from you, that is God promise to those that serve. peradventure sickness attack, you remind God of His promise. Remember God is a covenant keeping God. { proverb 13:17, John 15:2} 

Nothing will die in your hand premature: Verse 26 says, none will cast their young. It means God will not allow anything to die in your hand. No ambition, dream, vision, business, ideas, ministry, child etc will die without fulfilling their purpose.

It leads to fruitfulness: The opposite of fruitfulness is barrenness, stagnation, poverty, visionless, ignorance. When you serve God, be sure of God's ultimate blessing, grace for abundant fulfillment.

It guaranteed long life: Verse 27 says, the number of your days I will fulfill. The bible says, that the labourers are few but the harvest is plenty. So if you are a labourer, God will be committed to keeping you safe for the continuity of His work.  

Be born again: The first aspect of serving God is to present your body as a living sacrifice, holy and acceptable before God {Romans 12:1}. That is where it start from, you can't serve God in sinful life, if you do the service is a waste of time, energy and resources. 1 Samuel 15:22 says, Obedient is better than sacrifice.

Through Soul Winning Endeavour: 2 Corinthians 5:18-20 says,,,, that Christ has reconciled us back to God, so we ought to reconciled the unsaved back to God.  We are Christ ambassador here on earth, so we must represent His interest while on earth. The only commandment Christ gave his disciple is to go and preach the gospel to all creature {Mark 16:15}.

Serve God with your physical energy: You must join a department or unit in your church to serve. When you serve in any unit in your local church with all your heart, your pastor or any other person does not serve much better than you. Yes anywhere you is much important, because the pastor can't preach, usher, sing among others.

Serve God through your financial commitment: Promote God's kingdom through your giving, such as tithes, offering{Malachi 3:8-10}, first fruit(Proverb 3:9) and supporting church project. Remember, you are not giving it to anyone but rather to God and He alone can reward you. (Mathew 6:19-21).

Serve God through giving to the poor and needy: Giving to the poor is our Lords commandment (Mathew 25:43-44). You are blessed for others not just yourself only, everything you have is a gift from God, 1 Corinthians 4:7 says,,,, and what hast thou that thou did not received,,,.

Here are some scripture references on serving God endeavour.
Romans 12:4-7 For as in one body we have many members, and the members do not all have the same function, so we, though many, are one body in Christ, and individually members one of another. Having gifts that differ according to the grace given to us, let us use them: if prophecy, in proportion to our faith; if service, in our serving; the one who teaches, in his teaching;

Malachi 3:17-18 They shall be mine, says the LORD of hosts, in the day when I make up my treasured possession, and I will spare them as a man spares his son who serves him. Then once more you shall see the distinction between the righteous and the wicked, between one who serves God and one who does not serve him.

Colossians 3:23-24 Whatever you do, work heartily, as for the Lord and not for men, knowing that from the Lord you will receive the inheritance as your reward. You are serving the Lord Christ.

1 Peter 1:12 It was revealed to them that they were serving not themselves but you, in the things that have now been announced to you through those who preached the good news to you by the Holy Spirit sent from heaven, things into which angels long to look.

John 12:26 If anyone serves me, he must follow me; and where I am, there will my servant be also. If anyone serves me, the Father will honor him.

1 Thessalonians 1:8-10 For not only has the word of the Lord sounded forth from you in Macedonia and Achaia, but your faith in God has gone forth everywhere, so that we need not say anything. For they themselves report concerning us the kind of reception we had among you, and how you turned to God from idols to serve the living and true God, and to wait for his Son from heaven, whom he raised from the dead, Jesus who delivers us from the wrath to come.

Hebrews 6:10 For God is not unjust so as to overlook your work and the love that you have shown for his name in serving the saints, as you still do.

Romans 12:1 (KJV) I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service.