Catholics pray to saints for the same reason: b/c it logically follows from what we believe (and what the Bible teaches) about the Body of Christ. One way to show this is through the following syllogism:
- Members of the Body ask for each other's prayers (cf. Rom 15:30; Eph 6:19; Col 4:3-4; 1 Thes 5:25; 2 Thes 3:1; Heb 13:18)
- Members of the Body pray to God for each other (cf. Mt 5:44; Acts 8:15; 9:40; 28:8; 2 Cor 9:14; 13:9; Eph 6:18; Phil 1:9,19; Col 1:3,9; 2 Thes 1:11; 1 Tim 2:1; Phm 1:22; Jas 5:14,16; 3 Jn 1:2)
- The saints in heaven, as persons filled with grace and united to Christ, are:
- a. alive (cf. Jer 15:1; Mt 17:1-3; 22:32; Rom 8:13,35-39; 1 Cor 15:54-55), and
- b. members of the Body (cf. Rom 12:4-5; 1 Cor 12:13,26; 2 Cor 2:5; Eph 1:9-10; 2:19-21; 4:15-16,25; Col 2:18-19; Heb 13:3)
- Therefore, we can ask for their prayers (which is what we do when we pray to them) and they can pray for us, just like any other member of the Body.
Scripture tells us that the members of the Body, in their connection to the head, are also connected to each other (see 3b above). If we aren't, if we are divided so that there is the Body of Christ in heaven and the Body of Christ on earth, then that means Christ has two bodies. But, Scripture tells us that we are all united in one body (cf. Rom 12:4-5; 1 Cor 10:17; 12:12-13,20; Eph 4:4; Col 3:15). That union is what allows me to bring my concerns to the saints in heaven in the same way that I am able to bring my concerns to my Christian brothers and sisters on earth.
This, along with the verses that show their awareness of our actions (cf. Psa 34:7; Mt 18:10; Lk 15:7-10; 1 Cor 4:9; Heb 12:1) and their intercessory role (cf. Job 33:23-24; Jer 15:1; Zech 1:12-13; Heb 1:13-14; Rev 5:8; 6:9-11; 8:3-4), proves that the saints in heaven do in fact hear our prayers and that a communication can exist between the saints in heaven and the saints on earth. So, there is nothing to prevent the premises above from reaching their logical conclusion.
What all of this shows is that praying to the saints follows naturally from what Catholics believe (and what the Bible teaches) about the Body of Christ. The only way you can say that I have not defended the conclusion is to refute one of my premises. That is your task.........not to demand from me that I give you some explicit Scriptural command to pray to the saints.