Paul commends the Philippian church by reminding them of how, at the first preaching of the gospel, after he departed from their region (Macedonia), they shared with him in the matter of giving and receiving (4:15-16). At that point, they were the only church that took the initiative to send support to Paul. Even when he was still in Macedonia, at Thessalonica, more than once they sent gifts to him. Apparently those gifts were not enough to provide full support, because he reminds the Thessalonians how he worked with his hands to provide for his needs when he was with them (2 Thess. 3:7-9). But right from the start of their Christian experience, the Philippians had given.
Jesus taught the same principle in Luke 16:10-13. After giving the parable of the unrighteous steward, which has to do with money, He said, “He who is faithful in a very little thing is faithful also in much.” He goes on to show that the “little thing” is our use of “unrighteous mammon,” or money. If we are faithful in how we use our money to advance His kingdom, the Lord will then entrust “true riches” to us (16:11) which, in the context, are souls. If we want God to entrust us with souls, we begin by proving our faithfulness in what to us is a “big thing,” but to God is a “little thing,” the use of our money. That’s His test. So financial faithfulness, which includes giving, but also how we manage all the material goods God has entrusted to us (earning, spending, saving), should be one of the first lessons we learn in our Christian walk.