Serve the Lord with Gladness 
Make a joyful noise unto the LORD, all ye lands. Serve the LORD with gladness: come before his presence with singing. Know ye that the LORD he is God: it is he that hath made us, and not we ourselves; we are his people, and the sheep of his pasture. Enter into his gates with thanksgiving, and into his courts with praise: be thankful unto him, and bless his name. For the LORD is good; his mercy is everlasting; and his truth endureth to all generations. 
(Psalms 100:1-5)
Many professing Christians take the blessings that God has bestowed upon us for granted, not perceiving the privilege that is ours, the thankfulness due to Him, and the gladness of heart. 
It even goes to the thankfulness and gladness of being able to give something back to Him that gave us Life. In the old Covenant it was tithing: 
Thou shalt truly tithe all the increase of thy seed, that the field bringeth forth year by year. And thou shalt eat before the LORD thy God, in the place which he shall choose to place his name there, the tithe of thy corn, of thy wine, and of thine oil, and the firstlings of thy herds and of thy flocks; that thou mayest learn to fear the LORD thy God always. And if the way be too long for thee, so that thou art not able to carry it; or if the place be too far from thee, which the LORD thy God shall choose to set his name there, when the LORD thy God hath blessed thee: Then shalt thou turn it into money, and bind up the money in thine hand, and shalt go unto the place which the LORD thy God shall choose: And thou shalt bestow that money for whatsoever thy soul lusteth after, for oxen, or for sheep, or for wine, or for strong drink, or for whatsoever thy soul desireth: and thou shalt eat there before the LORD thy God, and thou shalt rejoice, thou, and thine household, 
(Deuteronomy 14:22-26)
While this is not a teaching on tithing, it shows how one's heart should be when coming before the Lord. 
You see, the Lord God Loves us and wants us to be happy and glad in serving Him. 
For he remembered his holy promise, and Abraham his servant. And he brought forth his people with joy, and his chosen with gladness: And gave them the lands of the heathen: and they inherited the labour of the people; That they might observe his statutes, and keep his laws. Praise ye the LORD. 
(Psalms 105:42-45)
The purpose of tithing is not to keep your church in funds. The purpose of giving is to show the Lord in a practical manner that you and I love Him enough to be happy in our obedience. 
Isn't Christian giving more than mere "tithing"? Doesn't it show a grateful heart? 
Then came together unto him the Pharisees, and certain of the scribes, which came from Jerusalem. And when they saw some of his disciples eat bread with defiled, that is to say, with unwashen, hands, they found fault. For the Pharisees, and all the Jews, except they wash their hands oft, eat not, holding the tradition of the elders. And when they come from the market, except they wash, they eat not. And many other things there be, which they have received to hold, as the washing of cups, and pots, brasen vessels, and of tables. Then the Pharisees and scribes asked him, Why walk not thy disciples according to the tradition of the elders, but eat bread with unwashen hands? He answered and said unto them, Well hath Esaias prophesied of you hypocrites, as it is written, This people honoureth me with their lips, but their heart is far from me. Howbeit in vain do they worship me, teaching for doctrines the commandments of men. For laying aside the commandment of God, ye hold the tradition of men, as the washing of pots and cups: and many other such like things ye do. And he said unto them, Full well ye reject the commandment of God, that ye may keep your own tradition. For Moses said, Honour thy father and thy mother; and, Whoso curseth father or mother, let him die the death: But ye say, If a man shall say to his father or mother, It is Corban, that is to say, a gift, by whatsoever thou mightest be profited by me; he shall be free. And ye suffer him no more to do ought for his father or his mother; Making the word of God of none effect through your tradition, which ye have delivered: and many such like things do ye. And when he had called all the people unto him, he said unto them, Hearken unto me every one of you, and understand: There is nothing from without a man, that entering into him can defile him: but the things which come out of him, those are they that defile the man. If any man have ears to hear, let him hear. And when he was entered into the house from the people, his disciples asked him concerning the parable. And he saith unto them, Are ye so without understanding also? Do ye not perceive, that whatsoever thing from without entereth into the man, it cannot defile him; Because it entereth not into his heart, but into the belly, and goeth out into the draught, purging all meats? And he said, That which cometh out of the man, that defileth the man. For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders, Thefts, covetousness, wickedness, deceit, lasciviousness, an evil eye, blasphemy, pride, foolishness: All these evil things come from within, and defile the man. 
(Mark 7:1-23)
Some additional passages of Scripture to bless you and make you think - a little bit: 
Blessed be the Lord, who daily loadeth us with benefits, even the God of our salvation. Selah. 
(Psalms 68:19)
Let us come before his presence with thanksgiving, and make a joyful noise unto him with psalms. 
(Psalms 95:2)
*A Psalm of David.* Bless the LORD, O my soul: and all that is within me, bless his holy name. Bless the LORD, O my soul, and forget not all his benefits: Who forgiveth all thine iniquities; who healeth all thy diseases; Who redeemeth thy life from destruction; who crowneth thee with lovingkindness and tender mercies; Who satisfieth thy mouth with good things; so that thy youth is renewed like the eagle's. 
(Psalms 103:1-5)
O give thanks unto the LORD; call upon his name: make known his deeds among the people. Sing unto him, sing psalms unto him: talk ye of all his wondrous works. Glory ye in his holy name: let the heart of them rejoice that seek the LORD. Seek the LORD, and his strength: seek his face evermore. Remember his marvellous works that he hath done; his wonders, and the judgments of his mouth; 
(Psalms 105:1-5)
Then they cry unto the LORD in their trouble, and he saveth them out of their distresses. He sent his word, and healed them, and delivered them from their destructions. Oh that men would praise the LORD for his goodness, and for his wonderful works to the children of men! And let them sacrifice the sacrifices of thanksgiving, and declare his works with rejoicing. 
(Psalms 107:19-22)
What shall I render unto the LORD for all his benefits toward me? I will take the cup of salvation, and call upon the name of the LORD. I will pay my vows unto the LORD now in the presence of all his people. 
(Psalms 116:12-14)
Honour the LORD with thy substance, and with the firstfruits of all thine increase: So shall thy barns be filled with plenty, and thy presses shall burst out with new wine. My son, despise not the chastening of the LORD; neither be weary of his correction: For whom the LORD loveth he correcteth; even as a father the son in whom he delighteth. Happy is the man that findeth wisdom, and the man that getteth understanding. For the merchandise of it is better than the merchandise of silver, and the gain thereof than fine gold. She is more precious than rubies: and all the things thou canst desire are not to be compared unto her. Length of days is in her right hand; and in her left hand riches and honour. Her ways are ways of pleasantness, and all her paths are peace. She is a tree of life to them that lay hold upon her: and happy is every one that retaineth her. 
(Proverbs 3:9-18)
Behold that which I have seen: it is good and comely for one to eat and to drink, and to enjoy the good of all his labour that he taketh under the sun all the days of his life, which God giveth him: for it is his portion. Every man also to whom God hath given riches and wealth, and hath given him power to eat thereof, and to take his portion, and to rejoice in his labour; this is the gift of God. For he shall not much remember the days of his life; because God answereth him in the joy of his heart. 
(Ecclesiastes 5:18-20)
Grace be unto you, and peace, from God our Father, and from the Lord Jesus Christ. I thank my God upon every remembrance of you, Always in every prayer of mine for you all making request with joy, For your fellowship in the gospel from the first day until now; 
(Philippians 1:2-5)
Charge them that are rich in this world, that they be not highminded, nor trust in uncertain riches, but in the living God, who giveth us richly all things to enjoy; 
(1 Timothy 6:17)
You might say, "why with gladness? Servitude is a serious business." 
Yes, it is, isn't it, if you serve someone to whom you owe loyalty because of your salary every week. 
But what about if you willingly serve someone out of love? 
Do you serve your marriage partner out of love? 
How about someone who saved your life, say by pulling you alive out of a burning motor car and risking his or her life in doing so? 
What about the Person who saved your everlasting life? He who was willingly tortured to death for you, to show His love and sincerity. 
How self-ish can we be?
Like this?
Our fathers understood not thy wonders in Egypt; they remembered not the multitude of thy mercies; but provoked him at the sea, even at the Red sea. Nevertheless he saved them for his name's sake, that he might make his mighty power to be known. He rebuked the Red sea also, and it was dried up: so he led them through the depths, as through the wilderness. And he saved them from the hand of him that hated them, and redeemed them from the hand of the enemy. And the waters covered their enemies: there was not one of them left. Then believed they his words; they sang his praise. They soon forgat his works; they waited not for his counsel: But lusted exceedingly in the wilderness, and tempted God in the desert. And he gave them their request; but sent leanness into their soul. 
(Psalms 106:7-15)
or this?
Praise ye the LORD. O give thanks unto the LORD; for he is good: for his mercy endureth for ever. Who can utter the mighty acts of the LORD? who can shew forth all his praise? Blessed are they that keep judgment, and he that doeth righteousness at all times. Remember me, O LORD, with the favour that thou bearest unto thy people: O visit me with thy salvation; That I may see the good of thy chosen, that I may rejoice in the gladness of thy nation, that I may glory with thine inheritance. We have sinned with our fathers, we have committed iniquity, we have done wickedly. 
(Psalms 106:1-6)
How often do we each pause, take time out, praise our God with or without music accompaniment, forgetting ourselves and our worldly striving and make music in our hearts as a sweet savour to our Lord? 
How about a happy prayer to bless God and make Him glad? 
Oh that men would praise the LORD for his goodness, and for his wonderful works to the children of men! For he satisfieth the longing soul, and filleth the hungry soul with goodness. Such as sit in darkness and in the shadow of death, being bound in affliction and iron; Because they rebelled against the words of God, and contemned the counsel of the most High: Therefore he brought down their heart with labour; they fell down, and there was none to help. Then they cried unto the LORD in their trouble, and he saved them out of their distresses. He brought them out of darkness and the shadow of death, and brake their bands in sunder. Oh that men would praise the LORD for his goodness, and for his wonderful works to the children of men! 
(Psalms 107:8-15)