Then one of the twelve, called Judas Iscariot, went unto the chief priests. And said unto them, What will ye give me, and I will deliver him unto you? (Matt 26:14, KJV)
Judas must have thought that Jesus was an earthly king destined to over throw the Romans and establish a kingdom. He might have reasoned that being a disciple will earn him a ministerial position in the impending kingdom. So he “gave” his time and energy into Christ’s ministry. When the “reward” of following Jesus wasn’t forthcoming, he began stealing from the treasury. When it dawned on him that Christ’s kingdom is heavenly and he was wasting his time, he decided to cash in with the next available opportunity. Yes he was tempted (then entered Satan into Judas surnamed Iscariot, being of the number of the twelve. Luke 22:3KJV), but that was his demeanour anyway.

Many modern day Christians are Judases waiting to happen, they give (service, time, money, sacrifice) to God not out of love, but because they want something in return. Then when those things don’t happen frustration begins to set in. God is neither a pawnbroker nor a microfinance banker. He cannot be mocked or cajoled (and will be gracious to whom I will be gracious, and will shew mercy on whom I will shew mercy. Ex 33:19 KJV). Many Christians no longer have faith in God, but in the things they do for him. Jesus said; Ask , and it shall be given you (Matt 7:7KJV). Not ask and give, and it shall be given you. You don’t need to transact business with God to be blessed. If the Lord is your shepherd, you shall not want. And if you diligently seek him, he will reward you. (But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him. -Heb 11:6,KJV)

So, whatever you “give” to God (service, time, money, sacrifice) give cheerfully. “Every man according as he purposeth in his heart, so let him give; not grudgingly, or of necessity: for God loveth a cheerful giver”. (2 Cor 9:6-7, KJV)