Is donating to Christian missions different than donating to the church?
The New Testament commands and example of giving provides some insight into this question. The churches (ekklesia, assemblies) of Galatia and Corinth were told to take up collections every first day of the week to support the needs of Christians who were starving due to a famine and lay it aside so that Paul could receive the totality of it when he arrived, at which point it would be taken on to Jerusalem (1 Cor. 16:1-4). When it arrived, it would be given to the elderships of the churches in Judea (Acts 11:29-30), who would then exercise their responsibility of oversight (cf. 1 Tim. 3:1; Heb. 13:17) in determining how it would be dispersed. Churches were commanded to provide financial support for preachers and missionaries (1 Cor. 9:1-18), and we have several examples of churches providing financial support to Paul during his missionary travels (2 Cor. 11:7-9; Phil. 4:15-16). As to how the churches produced this financial support, the only method recorded in Scripture is the commands concerning Sunday free-will offerings of the members (1 Cor. 16:1-2; 2 Cor. 8-9). One could reasonably deduce that the elderships of each of these churches exercised oversight by determining the amount of money to be used to support preachers and missionaries, the amount used for benevolence, etc.
So when one gives to the church, their contribution will be used in various works done by that church under the judgment and supervision of that church’s leadership, of which missions could be a part. It could therefore be said that when one donates to the church, one might be donating to Christian missions in an indirect way based on the judgment calls of the church’s leadership. Yet we also read of individual disciples of Christ who contributed directly to the financial support of Christ and his apostles while they were involved in domestic mission work (Luke 8:1-3). Paul’s needs as a missionary were supplied both by churches and by “the brothers of Macedonia” (2 Cor. 11:9), who could have been contributing as individuals or giving Paul what the churches in Macedonia had collectively donated; the text does not specify. It is implied that Gaius donated directly to the needs of traveling missionaries (3 John 5-8). So we also have scriptural precedence for individual Christians donating directly to Christian missions outside of their donations to the church.
From these contrasts it is clear that there is a difference between donating directly to Christian missions and donating directly to the church, whose leadership would then disperse one’s donation to various works, among which might be Christian missions.