God makes a very serious accusation against His people through His prophet Malachi. "Will a man rob God? Yet you have robbed Me! But you say, 'In what way have we robbed You?' In tithes and offerings" (Mal. 3:8).
The word "rob" has two definitions: 1) to seize and carry off property of by unlawful violence or threat of violence, 2) to deprive a person something belonging or due, defraud (Funk and Wagnalls New Comprehensive International Dictionary). While there is no way we can take things from God by violence or force, we can fail to give God the things that are due to Him.
Our Contribution. These Jews were robbing God by withholding their tithes and offerings. This was commanded under the Law of Moses. Today, the Christian is not commanded to tithe (give ten percent), but we are to give as we prosper (1 Cor. 16:1-2), as we purpose in our heart (2 Cor. 9:6-7), liberally and cheerfully. In withholding our contribution, we are robbing the local church of funds needed to carry out the Lord's work, but we are also withholding a statement of worth and thanksgiving unto God. In doing this, we are only hurting ourselves (Mal. 3:9).
Our Worship and Praise. "Give to the Lord the glory due His name" (Ps. 96:8). We worship God because He is worthy of such. He is our Creator, Sustainer, and Savior. We rob God of His praise when we remain silent during the worship of the church, or worse yet, when we remain absent from the assemblies of the church.
Our Service. God has given His Son for our sins. The least we can do is give ourselves in His service. "I beseech you therefore, brethren, by the mercies of God, that you present your bodies a living sacrifice, holy, acceptable to God, which is your reasonable service" (Rom. 12:1, emphasis mine - HR). A dead sacrifice is good only once, but a living sacrifice has perpetual benefit. We entered into service unto the Lord when we were baptized into Christ. We are not our own. We have been bought with a great price (1 Cor. 6:19-20). We have been redeemed and purified for good works (Titus 2:14). To hold back any part or portion of my heart, soul, mind, or strength from God is to deprive Him of that which belongs to Him (Mark 12:30).
Our Testimony to Unbelievers. God has revealed His existence through His creation (Ps. 19:1; Rom. 1:18-20), His providential kindness (Acts 14:17), and His written revelation (1 Cor. 2:9-13). However, there is another way God's greatness is to be made known to the unbelieving world - through the lives of His people. We are to let our light shine before men. Our good works in service to God will cause them to acknowledge God's existence (Matt. 5:16). Our love and unity as brethren will give people a reason to believe Jesus is real (John 13:34-35; 17:20-21). We are robbing God when we fail to live in a way that causes the lost to see the Lord.
It is possible for us to rob God today, and we do so in more ways than just closing up our wallets and checkbooks when the plate is passed at church. We can deprive God of our praise, our service, and our testimony to the world. Christians are the richest people the world will ever know. May it never be said that you or I have robbed God!