Thank you for turning to Lifeway for help with your family's questions about suicide.
Let's be reminded first and foremost that a person's salvation (and thus a place in heaven) depends solely on whether he or she has trusted in Jesus as Savior and Lord. We can do no act good enough to earn or deserve salvation (Titus 3:5). Moreover, once we've turned in faith to Jesus as Savior we can do no act bad enough that ever will separate us from God's redeeming love (Rom. 8:38-39).
The Bible contains a number of accounts of suicide or requests for assisted suicide. Often included among the biblical cases are Abimelech (Judg. 9:54), Samson (Judg. 16:29-30), King Saul and his armorbearer (1 Sam. 31:4-5), Ahithophel (2 Sam. 17:23), King Zimri (1 Kings 16:18), and Judas (Matt. 27:5). Some Bible students include Jonah because of his request in Jonah 1:12.
Although there is not a biblical command that explicitly prohibits suicide (unless one includes suicide under the Sixth Commandment, "You shall not murder," in Ex. 20:13 and Deut. 5:17), each portrayal of this practice in Scripture has tragic overtones. The Bible portrays suicide or the request for assisted suicide as a desperate act by a deeply troubled individual.
Some have said that a true Christian would never seek to commit suicide; and if a person does commit suicide, that act is evidence he or she really was not a Christian. I do not find anywhere that the Bible teaches this. We know that genuine Christians sometimes can go through periods of depression and desperation. What we know for certain about suicide is that anyone contemplating it--Christian or not--needs loving help and hope before they commit the act.