There are varied thoughts on the subject of giving for the New Testament church. As in all things pertaining to doctrine we must look to the Pauline epistles for direction.

In First Corinthians we find the following passages dealing with giving.
The first purpose of Christian giving is to support the work of the Lord by paying ministers and missionaries who labor in the Word.
A soldier does not fight a battle supporting himself but rather receives monies and provision from those he fights for. (1 Corinthians 9:1-15///1 Ti 5:16-18) He asserts he has needs as does everyone and the meeting his needs is the responsibility of those for whom he fights.
The key verse being verse 14:
1 Co 9:[14] Even so hath the Lord ordained that they which preach the gospel should live of the gospel.

We are told in First Corinthians sixteen the offerings are to be gathered on the first day of the week.
The criteria for our giving is to be in proportion to how one has prospered. If one is struggling to pay their bills and put food on their table there is not a lot of prospering going on.
We also find another purpose of giving here which is to support another Christian work these offerings spoken of being sent to the poor ministry in Jerusalem.

Though in Second Corinthians we find in spite of being poor the churches of Macedonia found a way to give to the work of the Lord. This being a result of first giving themselves to the Lord. If God has your heart He also has your wallet. We find our giving is an extension of God’s grace towards us.

(11 Co 8:5-7)
Most seem to miss verse 8 where the Apostle clearly states that giving out of poverty is NOT a commandment but a sign of their love for the Lord. (11 Co 8:8)
As our prospering by God should be growing so should our gifts to the ministry. (11 Co 8:10)
As with anything we do for the Lord we must first be willing to allow the Lord to direct us. It all begins with the heart and attitude. (11 Co 8:11-12)
We find rather than putting away our abundance it should be a means to supply to someone’s need.
(11 Co 8:13-15)
We also find there should be an openness on how the gifts are used so there be no opportunity for the devil to try and hinder the work with accusations of malfeasance. (11 Co 8:16-21)
Finally we find, our giving is a proof of our love for the Lord and a testimony to others. (11 Co 8:23-24)

11 Corinthians 9:1-15
Continuing the teaching on giving we look to chapter nine of Second Corinthians. Our giving can be a means of encouraging others to give. Our giving should be budgeted and prepared. (11 Co 9:1-5)Our giving should be with the knowing the more we give the more we receive. (11 Co 9:6) The amount of our gift is a personal decision and not based on being commanded. Our giving should be willing and with gladness that we are able to give a portion of the blessing we have received back to the Lord. (11 Co 9:7)
God is able to prosper us and give us the right heart towards giving. Our giving is used for the minister who sows and we receive blessings and spiritual food from him. We then being fed grow in the Lord and with our growth impact the effect on those around us. (11 Co 9:8-11)
This brings praise to God by us showing our love and supplying to the spiritual needs of others. This being a new method of supporting a work of the Lord not being one of command but one of the willing heart. Realizing God has given His all for us. (11 Co 9:12-15)