How do we know the plan of salvation is a flawed concept?

Often, the phrase 'plan of salvation' suggests that God has outlined steps that a person must follow to obtain salvation. This notion is problematic as it implies that God has a part to play and that humans must contribute as well, thus framing salvation as a collaborative effort rather than a complete work of God. Scripture emphasizes that salvation is not a plan to be followed but a solution provided by Christ. The focus of the gospel should be the proclamation of Christ's completed work, not a set of instructions for man to execute.